March - Slow Warming Trend With Rain Chance This Weekend?

[Belmer]

The high in San Marcos for Monday ranges anywhere from 92-95 degrees.
That has to be approaching near record highs for this time of the year. It's only mid March..

[srainhoutx]

A warm and pleasant weekend is ahead for our Region with warmer temps at night and increasing dew points and humidity lending to late night/early morning low clouds and warm temps in the low 90’s across the Rio Grande Valley and West Texas and mid to upper 80’s further E. A weak front will slide S of the Red River Valley on Sunday and retreat N Monday leading to very warm temps approaching record highs for many locations as an Upper Ridge over the Desert SW leads to compression and W to SW winds.

A bit stronger cold front will pass across Texas on Monday afternoon/evening and quickly wash out and retreat N on Tuesday. A return flow off the Gulf will become established rather quickly and push inland across the Lone Star State. A very progressive pattern develops as strong blocking continues over the N Atlantic and Pacific moisture and associated storm systems move inland across the Pacific NW and traverse SE as a trough is carved out of the Eastern half of the Nation. Another storm system will take shape on Wednesday across the Plains with leeside cyclogensis drawing chilly air from Canada with a strong Polar front dropping slowly S. It does appear that an Upper Ridge will be confined to the Desert SW and ‘colder’ temps in the wake of the sharp front slide S and E of the Rockies. While there is a great deal of uncertainty as to the timing of the eventual passage of the cold front later next week, the ensembles do suggest a return of chilly air may well may a return for the eastern half of Texas. The Euro is suggesting pooling moisture across the NW Gulf and even a developing Coastal Low along the Middle/Upper Texas Coast while the GFS is slower with the front, thus less in the way of rain chances. With all the uncertainty in the medium range and with an ongoing drought, the sensible forecast would be to keep things dry until some consensus develops. It does appear more chilly air will work into our Region later next week regardless of the rainfall potential. We will see.

[Portastorm]

Several operational runs from both the GFS and Euro suggest some crazy, very unseasonably cold air coming down into Texas for the last 5-6 days of March. Today's 6z GFS seems to be the most extreme as of now.

[srainhoutx]

Several operational runs from both the GFS and Euro suggest some crazy, very unseasonably cold air coming down into Texas for the last 5-6 days of March. Today's 6z GFS seems to be the most extreme as of now.

While there is some timing differences with the 12Z Euro being a bit faster, the GFS as well as the Canadian do agree that a sharp cold front will affect many locations E of the Great Basin into the Plains. It does appear that the jet stream pattern that has been prevalent across the Gulf will retreat a bit N and shift the storm track closer to our Region. Let's hope enough moisture from the Gulf can move inland mid next week and allow for some rainfall potential before that chilly air shuts the Gulf down once again.

12Z GFS:

03152013 12Z GFS 12zgfs850mbTAnomalyNA228.gif

12Z Euro:

03152013 12Z Euro 12zeurohourly850mbTempAnomalyNA192.gif

[SaskatchewanScreamer]

Well hello there Texas!

So.....so.....so very, very, very happy to have you take that pesky cold off our hands!

SS

(who is off now to oil up her fans)



p.s. remember *some* of you invited OLD MAN WINTER to North America!

[srainhoutx]

The overnight guidance with the assistance of a Winter RECON mission across the NE Pacific continues to advertise a sharp cold front later next week as the Major Regional Headliner.

This weekend is will be very pleasant across the Region with warm temps and a slight increase in moisture bringing late night cloudiness and windy conditions as a short wave passes well north across the Plains. A weak frontal boundary will remain near the Red River Valley before a stronger push of colder air finally drops that boundary S to Coastal Texas late Monday.

A return flow off the Gulf will quickly return mid next week as a much stronger short wave and much colder air dives S across the Plains and arrives across our Region late next Thursday into Friday. There remain some timing issues with the Euro being on the faster side of the guidance while the GFS and Canadian are about 12 hour slower and much drier. The ensembles and operational guidance do agree that temps will drop rather sharply with lows in the 30’s and daytime high struggling to get out of the 50’s next weekend. We’ll need to monitor the trends throughout the coming week to see if those temps correct and perhaps a bit cooler than forecast. Another issue will be the potential for lingering clouds behind the sharp front that could bring some chilly day temps next Saturday. Get out and enjoy this wonderful warm weather that we have for this weekend, because next weekend may come as a bit of a shock after the pleasant, quiet weather we have been experiencing the past 5 days.

03162013 00Z Euro Ensembles 00zecmwfenshourly850mbTempAnomalyNA192.gif

03162013 06Z GEFS 06zgfsensembles850mbTAnomalyNA180.gif

[Portastorm]

Yes indeed ... all three major medium range models -- the GFS, Euro, and Canadian -- are all showing a major cold front for next weekend for the Central and Eastern CONUS. And as you have astutely pointed out, srainhoutx, the ensembles also support this, so I would say the model support is fairly substantial at this point.

Based on what I'm seeing, it wouldn't be unreasonable to see a freeze in the northern half of Texas with high temps in the 40s for a day or two with 50s for Austin-San Antonio-Houston areas. And with temps so warm right now, this front will feel "wintry" to us due to temps dropping some 30 degrees.

Still a bit early though IMO to get excited. Let's see what the models suggest come early next week.

[jasons2k]

Article in today's Chronicle:

‘Real trouble’ in store if it doesn’t rain soon
By Eric Berger

Houston’s awfully dry. Since the middle of August, the city has gotten just a foot of rain over a time period when it should get twice that. We also have recorded six straight months of below-normal rainfall. And despite last Sunday’s splash of rain, March is likely to make it seven.

Because the lower rain totals have been registered during the coolest time of the year, the effects haven’t been deeply felt, but that could change soon as early spring turns to early summer.

“May and June are typically very wet months,” said John Nielsen-Gammon, a Texas A&M University professor and the state climatologist. “On one hand you can make up for a lot of drought during those months. On the other hand, if you don’t make up for it, you can be in real trouble come summertime.”

Unlike much of Texas, the Greater Houston area recovered nicely from the great drought of 2011 — the worst one-year drought in state history — during the first half of 2012. Soils turned wet, reservoirs were built up and aquifer levels recovered.

“In the Houston area, there was enough rain in 2012 that it effectively reset the drought clock,” Nielsen-Gammon said.

Across the rest of Texas, the drought that began in 2011 has never ended, the climatologist noted, as more than half of the state has remained continuously in a drought.

Despite the dry winter, most of Houston hasn’t yet officially dipped back into a drought. But according to the U.S. Drought Monitor, northern and northwestern portions of Harris County already have joined Montgomery and Waller counties in a moderate drought.

And with temperatures starting to climb — next week should see daytime highs in the low 80s — an ongoing lack of precipitation will be felt more acutely.

The region, in other words, needs April showers.

Unfortunately, the Houston/Galveston office of the National Weather Service says rainfall for the rest of March and April is shaping up as fairly light. In the short term that’s definitely the case, with the next chance of significant rain not coming until the end of next week, at the earliest.

eric.berger@chron.com  

[Texas Pirate]

Anyone know a rain dance????

'Real trouble' in store for Houston if it doesn't rain soon



http://www.houstonchronicle.com/news/ho ... mpid=btfpm

[srainhoutx]

The overnight guidance continues to advertise a sharp cold front will drop S into the Plains on Thursday bringing much colder temps and perhaps a chance of showers and storms, if capping can be broken.

We are heading toward a rather unusual pattern where the Artic Oscillation will drop to near record 6 standard deviations below normal along with a continued blocking West Based North Atlantic Oscillation extending E into Canada as well as a Pacific Ridge extending from Hawaii to Alaska. A strong storm system current NE of Hawaii will translate NE toward the Pacific NW with abundant tropical moisture and drop SE into the Southern/Central Rockies on Thursday. Lee side cyclogenesis will begin in earnest late Thursday as a dry line develops across W Texas. Moisture will begin to race inland from the Gulf Tuesday into Wednesday as pressure fall to our W and an onshore flow becomes established. An unseasonably strong push of much colder air that has been building across Canada will drop well S as a strong surface low develops over the Southern Plains. The best chance of rain would likely come in the form of a squall line that forms across West Texas on Thursday afternoon/evening and marches E into Friday. There still remains a lot of uncertainty about the rain chances due to capping and the persistent drought across our area. An Air Force C-130 Reconnaissance aircraft will sample the Gulf of Alaska area later this afternoon and hopefully that data will provide some clarity for the computer models. The most likely solution will be a quick shot of rainfall for Texas and much better chances of significant rains for Louisiana and points E. We’ll need to closely monitor the trends this week as there is a chance of freezing temps fairly far S into our Region with the first couple of set of Coastal Counties escaping any chance of those chilly temps. The Spring gardeners further inland will want to follow the forecast a bit more closely as tender plants may need to be protected from the late season cold snap next weekend into early the following week.



DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0356 AM CDT SUN MAR 17 2013

VALID 201200Z - 251200Z

...DISCUSSION...
WITH MEDIUM RANGE GUIDANCE IN GENERAL AGREEMENT...BROAD
CYCLONIC/PROGRESSIVE UPPER FLOW IS EXPECTED TO PREVAIL OVER MUCH OF
THE CONUS THROUGH MID/LATE WEEK. INITIALLY...LITTLE IF ANY SEVERE
THREAT IS EXPECTED ON DAY 4/WEDNESDAY.

BY DAY 5/THURSDAY...AT LEAST SOME SEVERE RISK MAY EXIST ACROSS THE
SOUTHERN PLAINS POTENTIALLY INCLUDING AREAS SUCH AS
WEST-CENTRAL/NORTH-CENTRAL TX AND PERHAPS INTO OK. AHEAD OF A
POSSIBLE SHORTWAVE TROUGH/JET STREAK CROSSING THE
ROCKIES...LOW-LEVEL MOISTURE /MAINLY LOWER 60S F SURFACE DEWPOINTS/
IS EXPECTED TO RETURN NORTHWARD ACROSS TX/PERHAPS SOUTHERN OK TO THE
EAST OF A DRY LINE AND SOUTH OF A LATE PERIOD SOUTHWARD-ACCELERATING
COLD FRONT. WHILE SOME SEVERE TSTMS MAY BE POSSIBLE THURSDAY
AFTERNOON/NIGHT...UNCERTAINTY EXISTS REGARDING THE DEGREE OF WARM
SECTOR CAPPING AND THE OVERALL EXTENT/LIKELIHOOD OF ANY SEVERE RISK.

BY DAY 6/FRIDAY...AT LEAST SOME SEVERE POTENTIAL COULD SPREAD
SOUTHEASTWARD IN ASSOCIATION WITH THE COLD FRONT...INCLUDING A BROAD
CORRIDOR FROM EAST/SOUTHEAST TX TO THE LOWER MS VALLEY/CENTRAL GULF
COAST REGION. LIMITED SPECIFIC PREDICTABILITY EXISTS AT THIS
JUNCTURE AND A 30 PERCENT EQUIVALENT SEVERE RISK AREA IS NOT
CURRENTLY EXPECTED.

..GUYER.. 03/17/2013

[ticka1]

just how cold next saturday? haveca trip to nacogdoches plan - would like to be prepared!

[sambucol]

just how cold next saturday? haveca trip to nacogdoches plan - would like to be prepared!

Yeah, what Ticka said. How cold next Saturday?

[srainhoutx]

It all will come down to which model you choose to believe has the better idea or handle on the upper air pattern ticka1 & sambucol. The GFS stands alone now suggesting that the front will not arrive until Saturday afternoon and the Euro/Canadian/Ukmet are suggesting a Thursday into Friday cold frontal passage. The fly in the ointment is what happens with a trailing upper air disturbance that the non American guidance is keying in on for next weekend as well. The GFS is dry other that a slight chance of storms further N late Thursday and then dry for the weekend with abundant sunshine while the non American guidance is 'hinting' a possible late season Winter Storm tracking across the Panhandle and Red River Valley next Saturday bringing the potential for wintry mischief and cloudy windy and very chilly conditions further S next weekend. The pattern is giving the guidance fits and that is the reason that the RECON missions have been flying the Gulf of Alaska. We'll have to wait a couple of more days to see what develops regarding the sensible weather expected. That said some very cold air has been building across Southern Canada and the Northern Plains. With a deep trough expected across the Central part of the US, we'll need to monitor the storm systems dropping SE from British Columbia and the Pacific NW this week. Those storms/upper air disturbances appear to have rather abundant tropical moisture to work with and the Southern jet will be rather close by over the Lone Star State this week. Frankly I am ready for warm temps and typical Spring weather after the pleasant weekend we just experienced. Although some rain would be nice as the drought is increasing and we could use some showers/storms to wash down all the pollen. We will see.

[srainhoutx]

A quick afternoon update regarding the late week time frame. The 12Z Operational GFS is still a bit bullish on keeping the Polar front draped across the Red River Valley while the 12Z GEFS is more aggressive in dropping the cold front well to the S along Coastal Texas. The WPC (formerly HPC) is sticking to the previous forecast with the ensembles handling the 500mb pattern a bit better than the operational guidance. The Canadian and Euro continue to advertise the front will drop S later on Thursday into Friday with a chance of wintry weather across the Panhandle and N Central Texas on Saturday as another upper air disturbance rides SE from the Pacific NW. The Arctic Oscillation remains very negative near record territory lending credence to what the ensemble guidance is suggesting.

EXTENDED FORECAST DISCUSSION...CORRECTED
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1151 AM EDT MON MAR 18 2013

VALID 12Z THU MAR 21 2013 - 12Z MON MAR 25 2013

SAW NO COMPELLING REASON TO MAKE MORE THAN COSMETIC CHANGES TO THE
OVERNIGHT GRAPHICS WITH THE AO INDEX AND BLOCKING (INVOF
GREENLAND) EXPECTED TO KEEP TROUGHING AND COLD...CANADIAN
AIRMASSES CYCLING THROUGH THE EASTERN HALF OF THE COUNTRY THROUGH
DAY 7. BELOW NORMAL TEMPERATURES FOR MUCH OF THE MEDIUM RANGE DUE
TO THE BLOCKY PATTERN DOWNSTREAM.

IN THE WEST...THE DAY 3 OCCLUDED CYCLONE MOVING INTO THE PACIFIC
NORTHWEST TRACKS VERY SLOWLY EASTWARD...WITH A SECOND BROAD
CYCLONE MOVING INSIDE OF 130W ON DAY 6/7.

SURFACE GRAPHICS MAINTAINED GOOD CONTINUITY USING THE BULK OF THE
ECMWF AND EC ENSEMBLE MEANS (27/12Z CYCLE) AND SOME OF THE 18/00Z
EC ENSEMBLE MEANS FOR DAYS 5-7...WHICH CONTINUE TO ADVERTISE A
SERIES OF MID-LEVEL IMPULSES EXITING THE ROCKIES AND TRACKING EAST
SOUTHEASTWARD ALONG A 'SUPPRESSED' POLAR FRONT DRAPED ACROSS THE
OZARKS...SOUTHEAST...THE GULF COAST AND INTO SOUTHERN TEXAS. MUCH
IF NOT ALL THE PRECIPITATION WILL FOCUS ALONG THIS MODIFIED
AIRMASS.

VOJTESAK


12Z GEFS:

03182013 12Z GEFS 12zgfsensembles500mbHeightAnomalyNA120.gif

12Z Euro:

03182013 12Z Euro 12zeuro500mbHeightAnomalyNA120.gif

12Z Canadian:

03182013 12Z Canadian f138.gif

[srainhoutx]

The SPC is keying in on areas across Central Texas as well as the Bryan/College Station to Huntsville to Lake Livingston Region N and W of Metro Houston for storm chances tomorrow. We will see...

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1143 AM CDT MON MAR 18 2013

VALID 191200Z - 201200Z

...NO SVR TSTM AREAS FORECAST...

...CENTRAL TX

NWLY MID-HIGH LEVEL FLOW IS EXPECTED TO PERSIST INTO THE DAY2 PERIOD
ACROSS THE SRN PLAINS AS UPPER TROUGHING SETTLES INTO THE OH VALLEY.
WITHIN THIS FLOW...A SRN STREAM SPEED MAX/SHORT-WAVE TROUGH IS
EXPECTED TO DIG ESEWD ACROSS THE SRN ROCKIES INTO CNTRL TX BY
20/00Z. IN RESPONSE TO THIS FEATURE...DAY1 FRONTAL SURGE OVER TX
SHOULD BRIEFLY STALL ACROSS THE HILL COUNTRY WHICH SHOULD ALLOW FOR
SIGNIFICANT BOUNDARY LAYER HEATING ACROSS PORTIONS OF SWRN TX.
WHILE SFC TEMPERATURES MAY WARM ENOUGH TO WEAKEN THE CAP ACROSS THE
WARM SECTOR...IT APPEARS WEAK WARM ADVECTION INDUCED BY THE
AFOREMENTIONED SHORT-WAVE WILL BE THE PRIMARY INSTIGATOR IN
CONVECTIVE DEVELOPMENT BY LATE AFTERNOON/EARLY EVENING ALONG/JUST
NORTH OF THE SFC FRONT. HOWEVER...4KM NAM FORECAST SOUNDING AT 21Z
FOR BBD EXHIBITS A CAP-FREE ENVIRONMENT WITH A 78/58 SFC TEMP/DEW
POINT. THIS YIELDS 1900 J/KG SBCAPE WITH MORE THAN FAVORABLE SPEED
SHEAR/TURNING FOR ROTATING UPDRAFTS. HAIL IS THE MOST LIKELY SEVERE
THREAT WITH THIS ACTIVITY BUT LOCALLY DAMAGING WINDS MAY ALSO
ACCOMPANY ANY STORMS THAT MANAGE TO DEVELOP NEAR THE WARM SECTOR.
CONVECTION SHOULD GRADUALLY DEVELOP/EXPAND IN AREAL COVERAGE DURING
THE EVENING HOURS WITH EWD PROGRESSION EXPECTED TOWARD THE SABINE
RIVER AS SHORT-WAVE ADVANCES TOWARD THE LOWER MS VALLEY. HAVE
INTRODUCED 5 PERCENT SEVERE PROBS TO ACCOUNT FOR THIS THREAT BUT A
CATEGORICAL SLGT RISK MAY ULTIMATELY BE WARRANTED ACROSS THIS REGION
IF IT BECOMES MORE CLEAR WARM SECTOR SUPERCELLS WILL DEVELOP.

[srainhoutx]

Just hit 87F in my back yard. This is the warmest I've seen since last Fall.

[unome]

here too http://w1.weather.gov/data/obhistory/KDWH.html

winds out of the west now though, looks like it will be north before too much longer http://hint.fm/wind/

[jasons2k]

Ditto.

And that's about all I can say until we see at least a good soaking of a widespread couple of inches+

[Texas Pirate]

Going to Dallas on Tuesday for Disability conference,
I hope I see rain - even if it has to be Dallas
I know its gonna be cooler .....

[srainhoutx]

Morning e-mail from Jeff:

Potential for showers and thunderstorms tonight into early Wednesday.

Cool front has moved off the coast overnight with a drier air mass now over the region and high temperatures today running a good 10 degrees lower than the record heat on Monday. Winds are already starting to shift around to the E and SE this morning and the frontal boundary will begin to return northward as a warm front by early afternoon. Aloft a powerful short wave disturbance over the Great Basin this morning will move ESE toward central and SE TX by late afternoon. Advection of colder air aloft over warm afternoon surface temperatures will make for an increasingly unstable air mass by late afternoon near/along the returning warm front. High resolution short term models show a rapid increase in thunderstorms late this afternoon from central TX into the northern sections of SE TX along the warm front as strong lift from the disturbance moves into an increasingly unstable air mass. Forecasted instability of 1000-1500 J/kg is expect north of I-10 by mid to late afternoon and this combined with favorable shear will support a few strong to severe thunderstorms with large hail being the primary threat. Low level winds typically back near warm fronts and potentially can enhance the tornado threat however surface dewpoints only near 60 suggest high cloud bases and this will likely reduce the tornado threat.

Initial storm mode will be isolated strong to severe supercells which will gradually transition into a broken line of thunderstorms. Storms should affect most of the areas north of I-10 and possibly all the way to the coast overnight. TX TECH WRF model shows most of the activity focused in the corridor from College Station to Liberty while the HRRR shows more widespread activity affecting nearly all of the area but does weaken any storms as they cross south of I-10 toward the coast. Current thinking is that storms will develop and affect much of the northern counties of SE TX this evening and then begin to weaken with the loss of heating and instability by late evening as they move south of I-10. The overall severe threat looks marginal with hail being the primary threat.

Another weak front crosses the area early Wednesday with a slight cool down. End of the week forecast continues to exhibit changes as models are not handling the arrival of a strong cold front over the weekend well. Yesterday models were driving this front off the coast on Friday, but have trended slower recently and have the front off the coast late Saturday. Temperatures will warm back into the 80’s by Friday ahead of this boundary. Flow just above the surface looks more SSW or SW which suggest capping may become entrained across the region which will help to limit rain chances. Not overly confident in the late week/weekend forecast at the moment with respect to any rain chances and just how much cold air will filter in behind the front and at what point.