RAIN is on the way!

RECORD LOW REPORT

TGIF everybody! FREEZING COLD start to our Friday in the 10s and 20s has given way to a pleasantly cool and beautiful afternoon with area wide temperatures in the 50s. Abundant sunshine and very dry air in place responsible for the nice warm-up this afternoon. Brand new record low of 21°F set this morning at the airport, shattering the previous record low of 28°F set back in 2011, 2007, and 1966. The temperature dropped to 26°F right in the city of Austin at Camp Mabry missing the record low of 25°F set all the way back in 1906 by only one degree! Keep in mind our "normal" low for this time of year based on a 30 year average (1981-2010) is 44°F at the airport and 49°F at Camp Mabry.

Here's a look at area wide low temperatures from across south central Texas this morning courtesy of the LCRA's Hydromet Network (a majority of these weather stations are located near/in creeks and river valleys...that's where the coldest temperatures are felt on clear, calm nights):

***Nowhere near as cold tonight, however, with the cool, dry air mass still in place and mainly to partly clear skies overhead, temperatures are going to drop into the upper 20s-lower 30s across low-lying/out-lying locations with lower to middle 30s expected in urban areas. Low spots within metro areas will receive a light freeze***

Rain Maker on the way!

An upper level low pressure system currently located over the northern Baja Peninsula will be moving east towards Texas over the coming days and as it does so will work to increase moisture levels at both the surface and aloft. Southwesterly winds aloft will work to pull Pacific moisture into the mid/upper levels of the atmosphere and a returning southeasterly surface wind will work to increase Gulf moisture here at the surface. You will notice the increase in clouds on Saturday. Disturbances embedded within the southwest wind flow aloft and the upper level lift associated with the approaching trough of low pressure will be sufficient in producing widespread rain across the area beginning early Sunday persisting through the day on Monday. Not looking for any strong storms or heavy rainfall, just a nice soaking light rain. Latest computer model guidance suggesting anywhere from 1/4 inch to as much as an inch of rain could fall across the area between Sunday morning and Monday evening...highest totals look to occur along and east of the Balcones Escarpment/Interstate 35 corridor.

Saturday: Cold start in the 30s gives way to a mostly cloudy/partly sunny and cool afternoon with highs in the upper 50s to near 60°F...rain possible by late evening across the Hill Country increasing during the overnight hours

Sunday: Widespread Rain/clouds likely with highs in the 50s, morning lows in the 40s

Monday: Widespread Rain/clouds likely with highs in the 50s, lows in the 40s

Water Vapor Analysis (Mid/Upper Level Moisture, not clouds)
As of 4 p.m. CST...(image courtesy of The University of Arizona)...really cool loop of this image can be accessed HERE)

500 mb Forecast Map: Vorticity (spin in the atmosphere)/Wind Speed/Height
Approximate location of the upper level low at 1 a.m. CDT Monday according to the GFS Forecast Model...a.k.a, yellow blog near Big Bend

Forecast Rainfall Accumulation
Images below courtesy of College of DuPage's Weather Page

NAM Model: 0.50 to 1.25 inches for I-35 corridor

GFS Model: 0.50 to 1 inch of rain for I-35 corridor 

***Beyond Monday the weather pattern looks to remain fairly unstable as of the latest forecast guidance that shows a trough, or line of lower pressure remaining parked over Texas much of next week. Translating to more in the way of cloud cover than sun and in turn cooler than normal afternoon temperatures generally in the 60s. Latest long range models do not show a return of Arctic Air over the next seven days***

El Niño (albeit weak) has officially Returned!! Great news for Texas

Yesterday, the Climate Prediction Center indicated that "borderline, weak El Niño conditions" have developed and they issued an El Niño Advisory stating that there is a 50-60% chance that El Niño conditions will continue through the Northern Hemisphere summer 2015. You're probably asking yourself, what is El Niño and how does it affect us here in Texas? Very simply, El Niño develops when WARMER THAN NORMAL sea surface temperatures are detected along the Equatorial Pacific...this above average water temperature has historically played a major role in giving us much WETTER and COOLER than normal weather conditions here in Texas. That's great news for us given our widespread agricultural and hydrological drought here in Texas. You can read their update by clicking HERE

Here's a look at the latest Pacific Sea Surface Temperature Anomaly released yesterday, March 5th (Image courtesy of NOAA):

***DAYLIGHT SAVINGS (SPRING FORWARD) TIME ARRIVES THIS COMING SUNDAY AT 2 A.M. Don't forget to set your clocks ONE HOUR FORWARD before going to bed SATURDAY NIGHT***

***PLEASE KNOW AND UNDERSTAND THAT THIS FORECAST IS SUBJECT TO CHANGE***

ICE THREAT Wed. into Thursday

FORECAST DISCUSSION:

Good Tuesday evening everybody. The low clouds, fog, mist and drizzle were never able to break up across a good portion of south central Texas today. Areas to the west of Austin and especially areas well southeast of Austin (La Grange, Giddings, and Houston among many others) were able to soar into the mid to upper 70s behind a warm front slowly creeping to the northwest. That warm, moist air advection (horizontal transport of air/moisture) is responsible for today’s widespread dense fog, mist and drizzle. Basically, the fog and mist are products of warm, Gulf air trying to compete with the lingering cool air mass over central Texas…the warm air is finally beginning to win as temperatures have now climbed into the upper 50s and lower 60s across a good portion of the Austin Metro Area. Warm advection continues through the night with temperatures actually expected to continue to rise a bit here in Austin. Low clouds, fog, mist and drizzle persist through the overnight hours into Wednesday morning with scattered light rain showers possible. A few sun breaks on Wednesday combined with continued warm air advection on southerly winds will allow for highs to top out in the upper 60s/lower 70s ahead of a powerful Arctic Front that will blow through the area somewhere between 2-6 p.m. Wednesday afternoon. The leading edge of that Arctic Air is just now beginning to move into the extreme northern Texas Panhandle. 

21Z (3 p.m. CST) Surface Analysis...leading edge of the Arctic Air just pushing into the extreme northern Texas Panhandle...image is courtesy of the Weather Prediction Center...and is available to you at anytime at this link: http://www.hpc.ncep.noaa.gov/sfc/namussfcwbg.gif

Rain/storms possible along and behind the front as it crosses the area tomorrow (Wednesday) afternoon. This is going to be one of those fronts where it drops from the 60s and 70s into the 30s and 40s within 20 minutes time. VERY WINDY conditions move in behind the front as the heavy, dense Arctic Air pours into the area. The National Weather Service has indicated that they may need to issue a WIND ADVISORY for portions of the area tomorrow afternoon. North winds sustained 20-25 mph will gust as high as 35-40 mph at times. Knowing that the Arctic Air is shallow and dense, it will force the warm, moist air up and over it aloft. Combine that moisture riding on top of the cold air with a series of disturbances moving overhead to provide lift and there is a concern for wintry precipitation across the area beginning early Wednesday evening and persisting I believe through midday Thursday. At this point in time, I’m concerned with the possibility of a freezing rain/sleet mix across a good portion of south central Texas, really from the Austin Metro Area and points north and west for possible ice accumulation on area roadways late Wednesday into early Thursday. Keep in mind that there may be school/work delays Thursday morning depending on how bad things get. How much wintry precipitation we are going to see? It’s not really for sure right now, however, we all know that it doesn’t take a lot around here to make a mess out of things. Given the nature of this weather setup (as it appears via the latest model information), freezing rain/sleet will be the biggest concern. However, a few snow flurries may be possible north and west of Austin Thursday morning where the cold air set-up will be more conducive for snow development. 

***In their latest forecast discussion, the National Weather Service stated that a WINTER WEATHER ADVISORY is likely to be issued by their next forecast update for much of south central Texas...a WINTER STORM WATCH/WARNING may be required for the the Hill Country based on future models' thinking about precipitation accumulation***

Here's their statement:

A WINTER WEATHER ADVISORY WILL LIKELY BE ISSUED IN THE NEXT
FORECAST PACKAGE...AND DEPENDING ON QPF TRENDS A WINTER STORM WATCH/WARNING MAY BE REQUIRED FOR THE HILL COUNTRY AND PORTIONS OF
CENTRAL TEXAS.

Great graphic from the National Weather Service Austin/San Antonio Forecast Office…issued just before 3 p.m. CST today:

-Areas shaded in pink and purple need to pay close attention to the forecast as icing looks to be a real threat (includes Austin Metro Area)

Forecast Precipitation Type across the area early Thursday morning according to the latest run of the GFS Model: