Heavy Rain & Cold on the way!

First off, I would like to wish each and every one of you a Happy Thanksgiving...I hope it is a beautiful day for all. Enjoy and cherish all that you are blessed with.

Forecast Discussion:

Good Wednesday afternoon everybody. Another heavy rainfall event looks to be coming together to bring much of the state widespread rainfall beginning tomorrow and persisting through the weekend. This type of weather set-up has the potential to produce flash flooding across the region. Please take that into consideration if you will be doing any traveling across the state this upcoming holiday weekend. It’s important to remember this slogan from the National Weather Service, TURN AROUND, DON’T DROWN if you come across a flooded roadway.

>>>Plentiful amounts of Gulf of Mexico moisture combined with Pacific moisture and moisture from now MAJOR Category 3 Hurricane Sandra (max. sustained winds of 120 mph) in the eastern Pacific will spread over Texas in the coming days. Plentiful moisture combined with the upper level dynamics of a large area of upper level low pressure over the western United States and a strong surface cold front will work together to efficiently wring out that moisture over Texas. The mid and upper level Pacific moisture streaming over the area, combined with the upper level dynamics of Hurricane Sandra, make the rain-making process over our area more efficient. The big dip in the jet stream over the western United States is effectively pulling that Pacific and Gulf moisture into the area.

The latest Infrared Satellite Imagery of Hurricane Sandra (courtesy of SSEC Real Earth)

 

>>>I’m thinking 1-4 inches of rainfall is likely over south central Texas between now and Sunday, with some isolated locations receiving upwards of 6 inches.

>>>Warm and muggy through Friday afternoon for much of south central Texas with temperatures in the 70s

>>>BIG Cold Front arrives Friday afternoon between 2-5 p.m. Temperatures take a nosedive behind the front from the 70s into the 40s on a gusty north wind…check out the forecast surface temperature map for 3 p.m. Friday afternoon (you don’t have to be a meteorologist to find this front…wow!)

 

Here's a closer look at south central Texas (courtesy of hazwx.com)...Friday's front is going to bring a 30+ degree drop in temperatures! 

 
 The National Weather Service Austin/San Antonio Forecast Office has issued a HAZARDOUS WEATHER OUTLOOK in anticipation of this event (see below):

This hazardous weather outlook is for south central Texas

Day one…today and tonight…

>NO hazardous weather is expected for today (Wednesday) or tonight

Days two through seven…Thursday through Tuesday

>Thursday night through Saturday…abundant moisture will interact with a cold front over Texas…resulting in a threat for locally heavy rainfall. Current projections are for the cold front to move into central Texas Friday afternoon and push into south Texas Friday night. Widespread rains are expected on both sides of the front…with a chance for locally heavy rainfall and localized flooding late Thursday night through Saturday.

Rainfall Totals Thursday through Sunday should average between 1 and 3 inches…with localized amounts up to 6 inches possible…especially over central Texas and the Hill Country.

Forecast Rainfall Accumulation between now and early Monday morning across the lower 48 courtesy of the Weather Prediction Center:

Notice the bulls-eye of potentially very heavy rainfall over north Texas and southeastern Oklahoma and Arkansas…that region could see upwards of 5-8+ inches of rain over the coming days

 

Thanksgiving Week Outlook

Forecast Discussion:
Area of surface high pressure that brought us the chilly temps over the weekend behind Saturday morning's windy cold front is now pushing east of the area. Now that we are on the backside (or western side) of this area of high pressure, the clockwise flow around it has allowed light southeasterly winds to return to south central Texas. Over the next couple of days, a trough, or dip in the jet stream aloft over the western United States will help surface pressures to drop across the plains east of the Rocky Mountains. Falling surface pressures to our north will help to increase the southerly flow across Texas. The deepening upper level trough to our west will pull the subtropical jet stream (southwesterly winds aloft) over Texas by the middle to end of the week. This southwesterly wind flow aloft will help to pump in Pacific moisture into the mid and upper levels of our atmosphere. At the same time, upper disturbances, or ripples in the wind flow aloft will help to kickoff on and off showers across the area (beginning as early as Wednesday). Latest forecast model guidance shows a tropical system forming in the eastern Pacific by the middle of the week. The southwesterly wind flow will help to pull some of the moisture from this tropical system over Mexico and into the southern plains. With two sources of moisture in play, heavy rainfall and minor stream and creek flooding may be possible Friday into Saturday.

Forecast 500mb Analysis Thanksgiving Evening (simple map, right?)...big upper level low over Nevada and California (blue shaded area)...reds over western Canada indicating high pressure, that will help to push the cold Canadian Air south into Texas on Friday...the upper level low will send moisture on top of that cold air to produce rain for us! 

Quick Weather Points

>>>We officially received our first freeze of the season in Austin this morning. Camp Mabry bottomed out at 32°F this morning. That freeze comes a week ahead of schedule.  

>>>The airport set two brand new record lows this weekend; 31°F Sunday morning (previous record: 32°F set back in 2005 & 1964) and 27°F this morning (previous record: 28°F set back in 1975)

>>>The average high and low for this time of year in Austin is 69°F and 48°F...as you can see, we were running well below average this weekend

>>>As of 2 p.m. C.S.T. temperatures are running in the lower to middle 60s across the area under mostly sunny skies...high clouds will be increasing from the west later this afternoon/evening and especially overnight and into the day tomorrow. 

>>>With increasing moisture expected across the state of Texas at both the low, mid, and high levels of the atmosphere, we can look for cloudy, balmy, and warm days ahead with highs rebounding into the 70s and lows rebounding significantly into the 60s. What a world of difference a change in wind direction makes this time of year.

>>>No more freezes expected through the end of the week; it will turn colder this weekend, but I think we will stay ABOVE freezing

Thanksgiving Day Forecast: 
Cloudy, mild, and muggy with highs in the middle to upper 70s, we will start the day in the mid to upper 60s. There is a 40-50% chance of on and off showers during the day and evening...the heaviest precipitation and possible storms should manage to stay north and west of the area...that changes though late Thursday evening into Friday (see below). 

Forecast Highs across the U.S. Thanksgiving Day


Black Friday Cold Front/Rain Chances
As it looks right now, the bulk of the rainfall with this next system looks to come late Thanksgiving into Sunday. A strong surface cold front will be moving across the state of Texas on Friday. This front will have some very chilly air behind it, setting up a large contrast in temperatures across the state. I'm thinking a 20-40 degree difference in temperatures on either side of the front. 

>>>Gusty north winds will move in behind the front. Temperatures will drop from the 60s and 70s ahead of the front into the 40s and 50s in a short amount of time.  

>>>The GFS Forecast Model is indicating that once the cold front passes through the area, it will stall, or really slow down just to our south and east and may in fact end up stalling near the Texas Coast. That would mean a 20-30 degree temperature difference between Austin and Houston on Saturday. We will have to wait and see what future model output shows.

GFS Surface Temperature Forecast (noon Friday)
There will be a 40-60 degree temperature difference across the state! You don't have to be a meteorologist to find the front on this map!

Potential Cold Heavy Rainfall Setup:
>>>As the front pushes into the area during the day on Friday, numerous to widespread showers and even some heavier downpours with embedded thunderstorms are likely to develop and persist through the day on Saturday as warm, moist Gulf air is forced to overrun, or move up and over the cold Canadian air at the surface. Combine that overrunning Gulf air with Pacific moisture streaming into the state and heavy rainfall may become an issue across south central Texas. As of right now, forecast models are showing the really heavy rains staying north and east of our area, but that could change.

>>>Temperatures on Saturday likely to stay in the 40s all day with rain falling.

How much rain are we talking? 
Latest forecast model guidance indicating a widespread 1-3 inches of rain possible across the area between now and Sunday evening...some locations may receive more than that (especially north and east of the area, as it looks right now where upwards of 3-5 inches of rain may fall)...there is still plenty of time to watch forecast rainfall accumulation

Wintry Precipitation?
>>>In my last blog I mentioned a threat for wintry precipitation across the area this coming weekend. Based on the latest forecast model guidance, freezing temperatures should stay well north of south central Texas...it looks like the majority of the wintry precipitation will fall in the Texas Panhandle. Portions of the Panhandle could get a very heavy snowfall by the weekend...check out the forecast accumulated snowfall map (this is just a forecast).

***Please know and understand that this is just a forecast...specifics may change over the coming days...remember to heed all watches/warnings/advisories issued by the National Weather Service***

  

Tomorrow's Cold Front

Forecast Discussion:
T.G.I.F. Everybody! Southerly winds have returned to the area in advance of tomorrow morning's cold front. Moisture levels are increasing across the area as evidenced by dew points in the 50s; this time yesterday, dew points were in the 40s. Dew points in the 60s have already made it as far north as the I-10 corridor. Southerly wind flow currently in place will abruptly come to an end tomorrow morning as the strongest cold front of the fall season thus far sweeps through the area. 

>>>A few rain showers will be possible along and ahead of the front early Saturday morning. Any showers that do in fact develop Saturday morning will be light. No significant rainfall accumulation is expected. However, if travel plans are taking you to south Texas or the coastal plains tomorrow, you may have to contend with some more widespread rains during the morning to early afternoon hours as the front moves through those locations.

>>>Wintry precipitation (sleet, snow, freezing rain) will NOT be an issue with this cold front

>>>Latest forecast model guidance continues to indicate the front moving through south central Texas between the hours of 6-9 a.m. Saturday morning...you will know when the front arrives as winds will switch abruptly to the north, pick up in intensity, followed by a noticeable and quick drop in temperatures and moisture. 

Cold Front's Forecast Position (7 a.m. Saturday Morning)>>>According to the high resolution NAM forecast model (click the image to make it larger)

Saturday's Forecast:
>>>Afternoon temperatures on Saturday will only manage the 50s behind the front. Areas north and west of Austin may stay in the upper 40s all afternoon. Add in a stiff north wind sustained between 15-25 mph (gusting higher than that) and there is definitely going to be a chill in the air. Sky conditions will start off cloudy on your Saturday and gradually become partly to mostly sunny by late morning into the afternoon hours. All of the area drops into the 30s Saturday night under a mostly clear sky; gusty north winds will be letting up by Saturday night. Locations north and west of the Austin Metro Area may receive a light freeze. Another very cold autumn night in store for ALL of south central Texas Sunday night as lows once again dip into the 30s; low-lying locations across ALL of south central Texas may receive a freeze (this includes low spots within the Austin Metro Area and points south and east).

Sunday's Forecast:
>>>High temperatures across the area on Sunday will only manage the 50s under a mainly sunny sky. Another very cold autumn night in store for ALL of south central Texas Sunday night as lows once again dip into the 30s; low-lying locations across ALL of south central Texas may receive a freeze (this includes low spots within the Austin Metro Area and points south and east).

Thanksgiving Week Outlook:
Warming trend ensues as early as Monday as light south southeasterly winds off of the Gulf return to the area. Southerly winds will effectively replenish low and mid level moisture across the area. As a powerful upper level storm system takes shape across the western United States, west, southwesterly winds at the upper levels of the atmosphere will strengthen and send Pacific moisture streaming across Mexico and into the atmosphere above Texas. Returning moisture at the surface and aloft over the area, combined with upper air disturbances, or ripples, in the subtropical jet (southwesterly wind flow) over the Lone Star State will effectively work together to bring rainfall chances back into the forecast for a majority of next week (including Thanksgiving). 

>>>With all of that said, get ready for a balmy, cloudy, and potentially wet Thanksgiving week around here after Monday. The majority of the rainfall next week, looks to be light to moderate, but some heavier rains may be possible late Thanksgiving Day into Black Friday as what looks to be an Arctic Cold Front approaches and moves through the state early Black Friday morning. 

Post Thanksgiving Day Arctic Blast Possible:
Per the latest long range forecast model guidance, this cold front looks to bring a widespread freeze to a good majority of south central Texas (including the Austin Metro Area). In addition to the threat of freezing temperatures, wintry precipitation MAY become an issue with this front for the weekend after Thanksgiving (as it looks right now, for areas north and west of Austin). There is still plenty of time to watch this weather system and a lot may change over the coming days and into next week, however, I felt it is important for you all to know and understand that there is the POTENTIAL for some very cold air and possible frozen precipitation next weekend. There is still plenty of time to watch this! 

Long range forecast guidance from the Climate Prediction Center indicating below average temperatures across a good chunk of the central and western United States (including Texas) for the days/week following Thanksgiving...they are also indicating above average rainfall. 

Saturday Cold Front

Forecast Discussion
Good Wednesday Morning. Beautiful day in progress across the Lone Star State behind yesterday's cold front. As of 10 a.m. C.S.T. temperatures are ranging from the 40s across west Texas, 50s across north and central Texas, and 60s and lower 70s across the coastal plains and the Valley under sunny skies statewide. Highs this afternoon with abundant sunshine and dry air in place will rebound nicely into the lower 70s after a very chilly start to the day in the 30s and 40s. We officially bottomed out at 43°F this morning at Camp Mabry and 38°F at the airport.

Wednesday Morning Low Temperatures across central Texas (LCRA Hydromet Network) 

>>>Beautiful fall weather will remain in place through Friday ahead of a strong cold front on Saturday. We can expect highs in the lower to middle 70s through Friday with overnight lows generally in the 40s and 50s across the area under mainly sunny/mostly clear skies<<<

Saturday's Cold Front

>>>According to the latest forecast model guidance, this looks to be the strongest front of the 2015 fall season thus far. The latest run of the GFS Model (also known as the American Model) has the cold front moving into the northwestern Hill Country early Saturday morning between 5-6 a.m. and crossing the I-35 corridor shortly thereafter between 6-9 a.m. and through the remainder of the area after that. The front should be completely through the state and into northern Mexico by mid to late afternoon. Some light rain showers may accompany the frontal passage early Saturday, but chances for significant rainfall are low. Rain along the front looks more likely for south Texas and the coastal plains. This looks to be a strong front and has the potential to drop temperatures into the 40s for a majority of the day Saturday...see the temperature timeline below according to the GFS Model. 

Forecast Surface Map Conditions for Saturday morning across the lower 48 courtesy of the Weather Prediction Center...the blue line with forward-facing blue triangles over Texas is the cold front



BIG Temperature Drop/Temperature Timeline 

>>>As mentioned earlier, this front will likely bring us the chilliest air of the fall season thus far. Latest forecast model guidance has us waking up to temperatures in the mid to upper 50s across the area early Saturday morning ahead of the front with some lower 60s from Austin south. 

Saturday Temperature/Sky Condition/Wind Timeline (for Austin, TX)

6 a.m. >>> Upper 50s to lower 60s (cloudy with some light rain possible) Wind: N/NE 5-10 mph

Forecast Frontal Position
(Notice the dark blue colors pouring into the northwestern Hill Country and the orange arrows...that's the leading edge of the cold front)

9 a.m. >>>Cold Front has arrived! Temperatures quickly dropping into the upper 40s and lower 50s behind the front on a strong and gusty north wind sustained temperatures already in the lower to middle 40s north and northwest of the Austin Metro Area...(cloudy with rain showers possible, however, showers that pop up would be quick-moving and light in nature) Wind: N 20-30 mph G35+ mph

Forecast Frontal Position
(Notice the blue shade has overspread the majority of the area and the arrows are yellow and orange and pointing south, signifying strong north winds)

Noon >>> Cloudy, cold, and windy with temperatures in the 40s area wide; Wind: N 20-25 mph G30+ mph (showers should be over)


3 p.m. >>> Cloudy, cold, and windy with temperatures in the 40s; Wind: N 15-25 mph G30+ mph


6 p.m. >>>Cloudy, cold, and windy with temperatures in the 40s; winds come down slightly, but still gusty; Wind: N 15-20 G25+mph

Mostly cloudy, cold and breezy night with lows dipping into the mid 30s to lower 40s across the area...a few spots across the extreme western and northern Hill Country may receive a light freeze

Forecast Lows Saturday Night (courtesy of Tropical Tidbits)

Sunday's Forecast and Beyond:

Sunday: >>>Cold start in the 30s and 40s will give way to a mostly cloudy and chilly afternoon with highs in the lower 50s

Monday: >>>looks like warmer and more humid Gulf Air moves back into the area with rain chances returning to the area.

>>>The Climate Prediction Center in their latest 6-10 day precipitation outlook forecasting above average rainfall across Texas next week



***Please know and understand that this is just a forecast and is likely to change to a degree over the coming days...the temperature timeline above for Saturday is simply a breakdown of what one particular computer model (the GFS), believes temperatures will look like on Saturday***

Tuesday Afternoon Update

Forecast Discussion:

Showers and thunderstorms moved through central Texas early this morning with relatively little fanfare. This morning’s storms have left behind 0.50 to 1.00 inch of rain across the Austin Metro Area, with lesser totals to our west and higher totals to our east. The heaviest rains by far this morning fell east of the I-35 corridor in Bastrop, Lee, and Fayette Counties. An LCRA (Lower Colorado River Authority) Rain Gauge northeast of Muldoon, TX is reporting 3.61 inches of rain in the past 24 hours. Bastrop County as a whole averaged between 1 to 1.50 inches of rain.

>>>Yesterday’s Tornado Outbreak<<<

*As the storms blew through the central Plains yesterday…several of the storms became severe with hail, high winds, and tornadoes…over 40 reports of tornadoes coming in yesterday from the Storm Prediction Center (see the map below…blue dots = reported strong winds, red dots = reported tornadoes, green dots = reported large hail)

Roger Hill, avid storm chaser and storm photographer captured this stunning picture of a tornado that developed between Groom, TX and Pampa, TX yesterday evening...it is going to be interesting to see what these tornadoes are going to be ranked on the EF-Scale...there was a report of a mile-wide tornado just southeast of Pampa, TX yesterday that caused some significant damage. Image below is courtesy of Roger Hill.

>>>Where are the storms currently? (as of noon Tuesday)<<<

The squall line (a.k.a. line of showers and storms) is now well east of the area and is currently working its way through east and southeast Texas where a TORNADO WATCH is currently in effect until 4 p.m. CST…this watch includes far east Texas, central and western Louisiana and extreme southwestern portions of Arkansas (see map below…counties within the bold red lines are under the tornado watch)…storms have slowed down somewhat as they pushed east of us…a slower forward movement will mean heavier rainfall totals for folks east of us.

>>>The upper level low pressure system responsible for all of this weather is currently pin wheeling over the Texas and Oklahoma Panhandles…this system will continue to push east through the day…as it does so, clouds will slowly be decreasing from west to east across the area…the far western Hill Country is already seeing some nice sun breaks<<<

>>>A few additional showers possible through the early afternoon hours...in fact, a handful of showers have popped up across Burnet and Blanco Counties right now...activity is moving southwest to north-northeast<<<

>>>Visible Satellite Imagery across Texas as of 11:45 a.m. CST Tuesday...clouds are slowly beginning to break up across the western Hill Country...that trend will continue across the remainder of the area through evening...clouds may be a bit stubborn though<<<

>>>Temperatures holding in the upper 50s to lower 60s across the area…highs should manage to rebound into the upper 60s to near, if not slightly above 70°F in a few locations (especially those areas that see more sunshine)<<<

>>>As clouds decrease across the area, breezy/gusty westerly winds will be pushing into the area as well, those westerly winds will effectively push very dry air into the area and set us up for a mostly clear and chilly night tonight<<<

>>>Lows dip into the 40s area wide tonight with some low-lying, out-lying locations possibly dipping into the mid to upper 30s (especially north and west of the Austin Metro Area) <<<

>>>Beautiful fall weather settles into the area tomorrow through Friday ahead of a cold front that looks to move across the area Saturday morning…this front has the potential to bring us the chilliest air of the fall season thus far and perhaps a few scattered light rain showers…I will be watching that over the coming days<<<

>>>Rest of the Week<<<

In one word>>>BEAUTIFUL! Mostly sunny/clear with highs in the 70s Wed. and Thurs. with overnight lows generally in the 40s…slightly cooler conditions possible Friday with a slight wind shift…then much chiller air moves in for the weekend!

Hope each of you has a wonderful rest of the week and are able to enjoy the nice weather heading our way.

Tuesday Morning Front/Storms

FORECAST DISCUSSION:

A very potent and dynamic pacific upper level low is currently located over the four corners region…out ahead of the upper level low at the surface, surface pressures are dropping along the front range of the Rockies…this drop in pressure has allowed winds to turn southerly across the area, efficiently allowing lots of gulf of Mexico moisture to roar back into the area…as this upper level low continues to push east through the evening and especially into the overnight hours, southerly winds will pick up across the area allowing for a continual feed of rich gulf moisture to continue to stream into the area ahead of an approaching surface frontal boundary being kicked east by the upper level low located back over the four corners region…the surface cold front is currently located across eastern New Mexico and far west Texas where gusty winds this afternoon have kicked up quite a bit of blowing dust…temperatures in El Paso have dropped into the 40s as of 5 p.m. CST after climbing into the 70s earlier today…winds are currently sustained out of the west in El Paso at 40 mph and gusting over 50 mph…earlier wind gusts approached 60 mph!

SEVERE WEATHER WATCHES/WARNINGS:

The Texas Panhandle, including the cities of Lubbock and Amarillo, is under a TORNADO WATCH until 9 p.m. CST...see map below 

NO WATCHES AND/OR WARNINGS ARE CURRENTLY IN EFFECT FOR SOUTH CENTRAL TEXAS

COLD FRONT/STORMS TUESDAY MORNING:

That cold front will be moving into south central Texas early Tuesday morning and moving through the I-35 corridor between 4-8 a.m. CST tomorrow morning

>>>A LINE OF HEAVY SHOWERS AND STORMS IS FORECAST TO DEVELOP ALONG THE LEADING EDGE OF THIS FRONT AND SWEEP ACROSS THE AREA<<<

>>>THE BIGGEST THREATS FROM THESE STORMS WILL BE HEAVY RAIN, GUSTY WINDS, AND DEADLY CLOUD TO GROUND LIGHTNING. FLASH FLOODING SHOULD NOT BE AN ISSUE DUE TO THE FAST-MOVING NATURE OF THIS STORM SYSTEM<<<

>>>THROUGH THE REMAINDER OF THE EVENING AND LATE NIGHT/OVERNIGHT HOURS SCATTERED LIGHT TO MODERATE DOWNPOURS AND EMBEDDED THUNDERSTORMS WILL BE POSSIBLE ACROSS THE AREA, AS WELL AS AREAS OF VERY LIGHT RAIN, MIST AND DRIZZLE. VISIBILITIES WILL COME DOWN OVERNIGHT AS THE HUMIDITY INCREASES OVER THE AREA, HOWEVER, DENSE FOG SHOULD NOT BECOME A CONCERN DUE TO THE FORECAST BREEZY SOUTHERLY WINDS TONIGHT INTO TUESDAY MORNING<<<

FORECAST RADAR AT 2 A.M. CST (22Z HRRR MODEL OUTPUT)

(Image courtesy of WeatherBell Models)

FORECAST RADAR AT 6 A.M. CST (HRRR MODEL OUTPUT)...THIS PARTICULAR MODEL BRINGS THE COLD FRONT AND ASSOCIATED LINE OF STORMS INTO THE I-35 CORRIDOR AROUND 6 A.M. CST

(Image courtesy of WeatherBell Models)

SEVERE WEATHER RISK:

We are under a marginal risk for severe weather here in central Texas, however, I feel the best chances for severe weather will remain north and west of us here in central Texas…regardless, strong storms capable of 40-50 mph winds will be possible Tuesday morning. Morning commute will be affected by the weather on Tuesday, so please do plan accordingly for that…please use a lot of common sense on roadways tomorrow morning and pack your patience. The good thing is that storms should be moving through here quickly. 

GRAB A JACKET/LIGHT SWEATER BEFORE HEADING OUT THE DOOR TOMORROW, YOU WILL NOTICE THE DROP IN TEMPS!

Much drier and cooler air mass moves into the area behind the cold front and storms tomorrow morning…behind the front, winds will abruptly shift from the south/southeast to the west/northwest and sustain themselves between 10-20 mph across the area with gusts in the 25-30 mph range on Tuesday…skies will slowly clear from west to east during the day Tuesday and we should be in for a mostly clear and chilly night across the area tomorrow night with lows in the 40s area wide. Highs Tuesday will only manage the upper 60s to lower 70s across the area.

COLD FRONT FORECAST POSITION (5 A.M. TUESDAY MORNING)...CHECK OUT THE TEMPERATURE CONTRAST ON EITHER SIDE OF THE FRONT!! 40s and 50s BEHIND THE FRONT, MUGGY 70s AHEAD OF IT...HIGHS TUESDAY AFTERNOON WILL RECOVER INTO THE 60s...40s AREA WIDE TUESDAY NIGHT/WEDNESDAY MORNING...SOME LOW-LYING OUT-LYING AREAS WILL DIP INTO THE 30s!

Image courtesy of WeatherBell Models (annotations done by me)

Forecast Lows across the state of Texas/south central United States Tuesday night/Wednesday morning...check out all of the 40s!! across central Texas...30s across West Texas!

Image courtesy of Tropical Tidbits

Rain Chances Increasing

FORECAST DISCUSSION:

TGIF Everybody! Cold front that blew through here Wednesday evening has really ushered in some nice, cool Canadian Air into the region that will be sticking around with us through the weekend. Temperatures are in the 60s area wide. Lots of Pacific mid and high level moisture overrunning the cool air mass in place over our area as evidenced by the mostly cloudy to overcast conditions across the area. That mid to high level moisture is streaming over the area in advance of our next upper level storm system that will be shaking things up once again for us over the coming days. Especially as we head into Monday/Tuesday of next week as a strong surface cold front and the best upper level dynamics move across the state of Texas.

Weekend Outlook:

As upper air disturbances, or ripples, in the upper level west southwesterly wind flow (subtropical jet stream) cross the area over the weekend, showers and thundershowers will be possible across the area beginning as early as tomorrow (Saturday) in advance of this dynamic upper level Pacific storm system. Light northeast wind flow at the surface will keep the cool air mass over us now in place through Sunday…that will ensure a cloudy, cool, and at times wet weekend across south central Texas. The activity that develops tomorrow and Sunday will NOT be severe, however, some moderate downpours and some cloud to ground lightning cannot be ruled out. Highs this weekend likely to remain chilly in the upper 50s to lower 60s across the area with lows generally in the 50s. It will be a good idea to keep the rain jacket and umbrella handy. 

Heavy Rainfall/Severe Weather Setup:

Southerly winds return to the area early Monday allowing Gulf of Mexico moisture to flood back into the area ahead of the main dynamics and cold front with our next approaching storm system. Given the dynamic nature of this next system, heavy rainfall and severe weather will both be a threat Monday and Tuesday of next week. Storms that develop late Monday into Tuesday will have the potential to become strong and/or severe with large hail, damaging winds, and isolated tornadoes. Of course, I will be watching the evolution of this system closely. As of right now, it looks like scattered showers and thundershowers will be possible during the day on Monday with the heaviest activity arriving late Monday into early Tuesday as the cold front crosses the area. It looks like a line of heavy showers and storms will develop along and immediately ahead of the front. If some stronger storms are able to develop out ahead of this forecast line of storms, those isolated storm cells will be the ones we need to watch closely for possibly producing a tornado or two. The biggest threats with a line of storms tends to be strong, gusty winds and small to medium sized hail. Of course, deadly cloud to ground lightning and heavy rainfall will be a threat from any storm that develops.

Forecast Model (Precipitation and sea level pressure) Map for early Tuesday...this particular model shows a line of heavy showers and storms moving across central and east Texas...pretty advanced map, but it does a good job of portraying what the situation may in fact look like on Tuesday morning 

Severe Weather Risk Areas:

The Storm Prediction has included south central Texas in the risk area for potential severe weather Monday/Tuesday of next week. We will be getting better details on this in the coming days. You can keep up with the latest severe weather outlooks created by the Storm Prediction Center by clicking HERE. The Storm Prediction Center really does a great job highlighting potential severe weather events days in advance and plays an integral role in keeping us safe on a daily basis.

Monday Severe Weather Risk (Yellow-shaded area)

Tuesday Severe Weather Risk (Yellow-shaded area)

Windy & Cooler Behind the Front

Behind the system, late Tuesday morning into early Tuesday afternoon a strong cold front looks to push into the area from the northwest and usher in some of the chilliest air we have so far this fall. This cold front will be preceded by a line of strong, potentially severe storms. Gusty northwest winds will usher in a much drier and cooler air mass into central Texas. This will set us up for cool afternoons in the 60s for the middle to end of next week with overnight lows dipping into the 40s area wide. Thursday morning is shaping up to be a chilly one with lows in the 30s possible across low-lying and out-lying areas of central Texas. Freezing temperatures should NOT be an issue with this particular front.

How much rain are we going to see?

It is difficult to pinpoint just how much rain this system is going to produce, however, it looks as we could be looking at a widespread 1-3 inches of rain across the area, with heaviest totals looking to come along and east of the IH-35 corridor, especially for areas north and east of south central Texas as evidenced in the Weather Prediction Center’s latest 5 day forecast rainfall accumulation map.

W.P.C. 5 Day Forecast Rainfall Accumulation:

We still have several days to watch the evolution of this system…remember, this is just a forecast and is subject to change and is likely to change slightly over the coming days. As always, please remember to heed all watches/warnings/advisories issued by the National Weather Service, Storm Prediction Center, etc.…

LET'S KEEP THOSE UMBRELLAS, RAIN BOOTS, AND RAIN JACKETS HANDY!

ON A GOOD NOTE, RECENT RECORD RAINFALL HAS PUT AN END TO THE AGRICULTURAL DROUGHT ACROSS SOUTH CENTRAL TEXAS...IT'S NICE TO SEE SO MUCH WHITE (A.K.A. DROUGHT-FREE) AREAS ON THIS MAP.

YELLOW AREAS = ABNORMALLY DRY 

BEIGE AREA = MODERATE DROUGHT

Veteran's Day Cold Front

FORECAST DISCUSSION:

Good Monday afternoon folks! Hope you all had a wonderful weekend. I’m already tracking our next upper level storm system currently located across northern California…this system will be progressing eastward across the Rockies and eventually out into the Great Plains over the coming days…as it does so, this system will develop a surface low pressure system across eastern Colorado and kick a cold front through the area during the day on Wednesday. As surface pressure continues to drop across the front range of the Rockies in response to the approaching upper level storm system, winds will become southerly across the area, forcing the front that moved through the area on Friday, back north as a warm front. This will effectively move Gulf of Mexico moisture back into the area as early as early Tuesday afternoon. You will feel that moist air by tomorrow afternoon and especially into Wednesday morning ahead of the cold front.

Upper Level Storm System's Current Position and Upper Level Wind Flow over the lower 48 as of early Monday afternoon:

Wednesday Storm Threat:

As a cold front interacts with the Gulf moisture in place, there is a 30-40% chance for showers and thunderstorms across the area midday Wednesday into the early afternoon hours. Highs will manage the middle to upper 70s across the area on Wednesday ahead of the front. Storms that develop along the front will be moving quickly, so rainfall accumulation should not be significant (generally less than 0.25 inches)…the best chances of rain will generally come along and east of the Highway 281 corridor. The Storm Prediction Center has included portions of south central Texas, from the I-35 corridor eastbound in a MARGINAL RISK for severe weather...the strongest storms should remain well north and east of south central Texas, however, some brief heavy rain, gusty winds, and cloud to ground lightning cannot be ruled out. The best upper level dynamics with this storm system will be too far north of here for any significant severe weather. With that being said, I also believe the best chances for showers and storms will remain well to our north and east. We will also need to monitor the potential for a capping inversion across the area, that may effectively squash rain chances…a capping inversion, or more simply a cap, is a layer of warmer, drier air that sometimes develops across the area in the mid layers of the atmosphere. Underestimating the strength of the cap can really mess up a forecast.

Veteran's Day Severe Weather Risk Areas (Correlate colors on this map with the table below) 

WHAT IS A MARGINAL RISK FOR SEVERE WEATHER?

Isolated severe thunderstorms possible...limited in duration and/or coverage and/or intensity...storms may produce winds of 40-60 mph, and/or hail up to 1" in diameter, and/or an isolated tornado...check out the great graphic below from the Storm Prediction Center

BEHIND THE FRONT:

Clearing and breezy behind the cold frontal passage Wednesday afternoon and evening as a drier and cooler air mass returns to the area setting us up for a pleasantly cool and comfortable Thursday and Friday with highs in the 60s and 70s and lows in the 40s and 50s ahead of our next storm system and chance for rain over the upcoming weekend…more details on that storm system in the coming days…as it looks now, this upcoming weekend has the potential to be wet and chilly. 

STORMY EVENING/OVERNIGHT

FORECAST DISCUSSION:

Good Afternoon folks! I’ve just finished analyzing and looking over all of the latest forecast model data and guidance. All of the ingredients are really beginning to come together to produce a potentially very stormy evening and overnight across south central Texas. The latest runs of the HRRR Model (High Resolution Rapid Refresh Model) which updates itself hourly with all of the latest weather and atmospheric conditions factored in, is painting a concerning picture for our area.

It’s just one of those days you can feel storms are coming.  Very warm and muggy out there right now with temperatures in the 80s…as of the latest data available from the Storm Prediction Center, the CAPE, Convective Available Potential Energy, the juice to keep storms going, is quite high across the area for early November. Plentiful moisture and CAPE, combined with approaching surface and upper level lift will provide a more than sufficient atmosphere for storms to develop and thrive. An approaching Pacific Cold Front will be the focus for the storms to develop. The front’s forward speed is going to be crucial in determining, just how long heavy storms and rain stick around.

Scattered heavy downpours and embedded thunderstorms have already begun to develop across the Hill Country, this activity is quickly moving off to the northeast into north central Texas where they are currently under a TORNADO WATCH until 8 p.m. CST. THE ONLY WATCH IN EFFECT FOR SOUTH CENTRAL TEXAS RIGHT NOW IS A FLASH FLOOD WATCH…HOWEVER, THAT MAY CHANGE AS WE HEAD INTO THE EVENING AND OVERNIGHT HOURS.

Latest forecast model guidance is indicating storm initiation along the I-35 corridor as early as 5 p.m. CST this evening…as it looks now, these storms will be capable of producing severe weather in the form of flash flooding, lightning, hail, gusty winds, and possibly an isolated tornado. REMEMBER, A THUNDERSTORM IS CONSIDERED TO BE SEVERE IF 1 INCH DIAMETER HAIL OR LARGER IS FALLING AND/OR THE STORM IS PRODUCING 58 MPH OR GREATER WINDS AND/OR A TORNADO IS PRESENT (CAN BE A RADAR INDICATED TORNADO).

***ALL IMAGES BELOW WERE PRODUCED BY THE HRRR MODEL MENTIONED ABOVE***

(THIS TENDS TO BE A RELIABLE MODEL, HOWEVER, PLEASE REMEMBER IT IS JUST A FORECAST TOOL AND GIVES US AN INDICATION AT WHAT CONDITIONS MAY BE LIKE LATER THIS EVENING)

FORECAST RADAR (5 P.M.)

FORECAST RADAR (8 P.M.)

FORECAST RADAR (MIDNIGHT)

FORECAST RAINFALL ACCUMULATION

Storms Return Thursday

FORECAST DISCUSSION:

El Niño has really begun to show its face across south central Texas over the past couple of weeks as two historic rainfall events have already occurred. Still confused on exactly what El Niño is? El Niño was given its name by Peruvian fisherman, because they noticed that fishing conditions deteriorated for some reason around Christmas time…the poor fishing conditions were determined to be caused by WARMER than normal waters across the equatorial Pacific. Warmer ocean water contains less nutrients for fish, less nutrients = bad fishing. El Niño, in Spanish, means the boy, and was given this name to refer to baby Jesus, because of noticeable warming of the water around Christmas-time. El Niños typically bring us WETTER AND COOLER than normal conditions across south central Texas during the fall and winter months, whereas, La Niñas, the opposite of El Niño, tends to bring us WARMER AND DRIER weather during the fall/winter months. Warmer than normal sea surface temperatures across the Pacific, and in this year’s case, much above normal water temperatures, provide more than sufficient fuel for developing Pacific storm systems, which, move from west to east across the northern hemisphere thanks to the prevailing westerly winds, known as the Westerlies. The subtropical jet stream takes on a more important role during El Niño years and pumps moist, tropical air north for Pacific storm systems to feed on. The amazing thing about both El Niño and La Niña is that their effects are felt on a global scale. The devastating fires and drought ongoing across much of Malaysia can be attributed to El Niño among many other odd weather events occurring across the globe.

Latest Global Sea Surface Temperature Anomaly (as of November 2, 2015)...notice the MUCH WARMER THAN AVERAGE sea surface temperatures across the Equatorial Pacific.

CLICK HERE TO WATCH A SHORT, BUT INFORMATIVE VIDEO ON EL NIÑO

STORMY THURSDAY/FRIDAY

Another upper level Pacific storm system is digging south and east over the western United States and will be approaching Texas late Wednesday into Thursday. Upper level divergence out ahead of this approaching upper level storm system creates low pressure at the surface. Falling surface pressure out ahead of the storm system will allow southeasterly winds to return to the area and ultimately allow rich, tropical Gulf of Mexico moisture to flood back into the area. Thursday into early Friday are going to be the days to really watch as that is when a surface cold front and its associated surface low pressure will move across the state of Texas. Upper level lift aloft in the upper levels of the atmosphere, combined with dynamic surface lift along the cold front, and plentiful amounts of moisture will generate a widespread chance for showers and storms Thursday into Friday. The Storm Prediction Center has already placed all of south central Texas in the MARGINAL RISK category for severe weather on Thursday with areas of the northwestern Hill Country and much of north central Texas under a SLIGHT RISK for severe weather. The Storm Prediction Center is highlighting the risk of severe hail across south central Texas, however, strong, gusty winds and isolated tornado cannot be ruled out.

Thursday Severe Weather Risk Areas (Dark green = MARGINAL, Yellow = SLIGHT)

How much rain are we going to see?

Latest forecast model guidance is estimating a widespread 1-3 inches of rain to fall with this next system, however, that will need to be monitored closely over the next several days. Some areas may have the potential to receive upwards of 4 inches. It is really going to depend on how quickly this cold front clears the area on Thursday/Friday. The heaviest rains will occur ahead, along, and immediately behind the front with lighter, more scattered rains lingering on behind the frontal passage into Saturday as cooler air filters into the area. The reason the rain is going to linger behind the main line/cluster of storms is that the upper level low to our west will take its time to cross the area. Until it does so, rain will be possible across the area. Highs likely to drop into the 60s Saturday and Sunday with lows in the 50s.

Weather Prediction Center's Composite Rainfall Accumulation map (valid today through Sunday)...they are forecasting 1-3 inches of rain across south central Texas

Please stay tuned to the latest forecasts over the coming days and please remember to remain weather aware. El Niño years have the potential to bring us a lot of surprises this fall/winter, so it’s always a good idea to be prepared and informed for whatever Mother Nature decides to throw at us.

Remember these phrases from the NATIONAL WEATHER SERVICE:

IF YOU COME ACROSS A FLOODED ROADWAY, TURN AROUND, DON’T DROWN

WHEN THUNDER ROARS, GO INDOORS