March: Warm Days To End The Month With Isolated Showers

[srainhoutx]

My total for the storm events March 8-11 was almost 4.5 inches of rain. The fog was as thick as thieves this morning with less the 1/4 mile visibility when I woke up. For those on 'Spring Break', enjoy the weather. Next week is looking eventful yet again...

[srainhoutx]

Morning e-mail from Jeff:

Prolonged rainfall event has ended with widespread totals of 2-4 inches across SE TX from Friday-Sunday….see Hydro section below.



Upper level storm system responsible for the rainfall event over the weekend has moved into the Midwest this morning with a lingering trough axis draped across the nearshroe waters and then inland over SW LA. Radar is fairly active over SW/SC LA where this axis has stalled out and recently there has been some weak development off the upper TX coast. Will need to watch these trends this morning to make sure offshore activity does not try and build northward and inland.



While the air mass in the mid and upper levels has dried out, the surface to 925mb level remains extremely moist and fog has developed across much of the area this morning. Should start to see the fog lift and burn off by mid to late morning. Warm and moist surface air mass will remain in place for the next week or so as southerly flow is maintained off the Gulf of Mexico. This will lead to cloudy/foggy mornings and partly cloudy afternoons with lows in the 60’s and highs near 80. The area will lie near the northern edge of the sub-tropical ridge over the SE US and Gulf of Mexico (similar to a summer like pattern) and with moisture levels marginal each day a few scattered showers/thunderstorms will be possible each afternoon. Noisy WSW upper level flow with a few embedded disturbances aloft could enhance these showers from time to time, but no time period stands out as a favored rainfall period over any other. Will throw in 20-30% each day through next weekend to cover this possibility.



Hydro:

Widespread rainfall over the weekend has led to rises on area watersheds.



A Flood Warning is in effect for the San Bernard River at Boling and East Bernard. The River is nearing flood stage at both forecast points and will likely rise above flood stage this morning. Impacts will be minor across Fort Bend and Wharton Counties.



Other rivers are rising across the area, but should remain below flood stage.



Weekend Rainfall:

Rainfall averaged from 1-4 inches across the region over the past 3 days. The highest totals (2-4 inches) were noted from the NW side of Downtown Houston across SE Montgomery County into central San Jacinto County and then northern Polk County. Another area of high totals was noted from the south side of College Station across northern Grimes County (4-6 inches).



3-day Rainfall Totals:

College Station: 3.91

BUSH IAH: 4.61

Hobby: 3.22

Galveston: 2.04

Bay City: 2.22

Caldwell: 2.43

Cypress: 2.30

Ratcliff: 4.67

New Ulm: 3.20

Tomball: 1.98

Conroe: 3.28

Palacios: 1.65

Sugar Land: 2.34

Wharton: 1.45

Huntsville: 2.89

Victoria: 1.85

[texoz]

Just to clarify. For Southeast, South and Central Texas, the rain chances (around 20%) each day this week are mostly for summer-like AFTERNOON showers to develop? I'm trying to plan some outdoor activities this week and it looks like the mornings should be okay???

[wxman57]

Just to clarify. For Southeast, South and Central Texas, the rain chances (around 20%) each day this week are mostly for summer-like AFTERNOON showers to develop? I'm trying to plan some outdoor activities this week and it looks like the mornings should be okay???

That's correct, just a slight chance of an afternoon sprinkle each day this week. Probably a bit of fog in the mornings. Highs 80-84 degrees each day (after today) - my kind of late winter!

[TexasBreeze]

It's going to be a great weather week!

[wxman57]

Here's a comparison of rainfall at my house last year vs. this year. I've already measured more rain than all of 2011 - nearly 22".

[srainhoutx]

The 12Z guidance is fairly good agreement of a possible severe weather episode next week for areas in the Central US. While we are a long way out in model world, this may well be our next weather headline maker and we'll monitor the trends in the coming week. Enjoy this great Spring like weather!

[Andrew]

The 00z CMC went bonkers with the trough for the middle of the next week. While this is in the long range period and resolution is greatly diminished, all three models (CMC, GFS & Euro) show a very amplified trough extending through the whole western U.S. From there models slow down the trough and some cut if off ( or almost cut it off) into a H5/ULL. The cmc keeps it attached but instead of sending it NE, continues to push it south all the way into central Texas with a fantastic setup for severe weather. Either way models have been persistent on dropping a very potent trough from the Pacific/ Canada region and now the key is how far south will it push or will the ridge undercut it sending it north (Like the GFS says it will). It is too far out to really know much now but keep an eye out.

[wxman57]

Latest GFS is about a day ahead of the 00Z Euro as far as next week's upper-level low movement. Both models keep the upper low center well to our NW - over the northern TX panhandle for the GFS and over Colorado for the Euro - before kicking the low out to the NNE. This could mean a bout of severe weather for northwest TX to north-central TX northward through OK/KS from late next Tue through Wed. Probably no severe storms here. Maybe a little rain here next Wed, possibly a thunderstorm. Too early to say if the "cold front" will make it through us or not. No cold air with it, though, even if it does move through.

Looks like we will be in the 80s for the next week, with lows in the upper 60s to low 70s. Can't beat that! Had a great ride after work yesterday - no winter coat and insulated tights needed for a change.

[srainhoutx]

The 12Z guidance continues the theme suggesting a deep Western trough with a cut off low meandering near CA/AZ as we head toward the weekend. The 'best' chance of any significant weather in Texas would be in the Panhandle/N Central and possibly N TX on up into the Southern/Central Plains. I really do not believe there will be enough push or eastward progression of the trough to bring any front into the area before late next week, if then. There were some scattered showers/sprinkles up here in NW Harris County a bit earlier and I suspect that will be about all we'll see here locally into early next week.

[texoz]

This leads me to believe we have seen the last of temps below 40 degrees in Texas, south of a line from Austin to College Station.

http://www.cpc.ncep.noaa.gov/products/p ... day.01.gif

[Ptarmigan]

Strong Thunderstorms Battered Louisiana Monday Night
http://www.accuweather.com/en/weather-n ... erst/62691

"There are a lot of slow-moving thunderstorms developing at the tail end of a frontal boundary," said Pigott. "Because the frontal boundary isn't moving, and wind flow that's directing these storms isn't moving very fast, we have thunderstorms that are moving over the same area over and over again."

I notice heavy rain events like this happen in a small area.

[srainhoutx]

The medium range guidance has come into better agreement as we look ahead toward the late weekend time frame into early next week. A very deep full latitude Western trough develops to our W with a deep cut off upper low spinning in the Great Basin by Saturday. Southerly winds will increase pumping rich tropical Gulf moisture across TX setting the stage for a possible significant, negative tilted trough approaching Central and SE TX Monday into Tuesday. There does appear to be a severe weather event for Monday into Tuesday of next week shaping up and warrants attention as another bout of very heavy rainfall and potential flooding due to training very strong storms slowly move E as the upper trough finally clears the area around mid next week. Some of the guidance suggests 5-6 inch or more rainfall for Central TX and points N. The heavy rains and storms are suggested to slowly translate E into SE TX on Tuesday. We'll need to monitor this situation closely as we are talking about the day 5-8 time frame, but all indications point that in the days ahead the chance for severe weather once again looks to affect the region. Stay Tuned!

DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0341 AM CDT WED MAR 14 2012

VALID 171200Z - 221200Z

...DISCUSSION...

LATEST MEDIUM RANGE GUIDANCE IS IN REASONABLE AGREEMENT REGARDING
THE EVOLUTION OF THE WRN U.S. TROUGH THIS WEEKEND. BOTH THE GFS AND
ECMWF ALLOW STRONGER FLOW ALOFT TO SPREAD ACROSS THE ROCKIES INTO
THE HIGH PLAINS BY DAY5. GIVEN THE EVOLUTION OF THE LONG WAVE
TROUGH IT APPEARS THAT A BROAD WARM SECTOR WILL HAVE SPREAD ACROSS
MOST OF THE PLAINS INTO THE SRN PROVINCES OF CANADA BY
120HR...SUNDAY. LATEST THINKING IS CONVECTION WILL LIKELY
CONCENTRATE ALONG THE DRY LINE/LEE TROUGH WHERE BOUNDARY LAYER
HEATING WILL BE MAXIMIZED AND THIS WILL COINCIDE WITH STRONGER FLOW
ALOFT THAT WILL SUPPORT ORGANIZED UPDRAFTS. SEVERE WILL LIKELY
ADVANCE DOWNSTREAM DURING THE DAY6 PERIOD BUT THE INCREASINGLY
MERIDIONAL NATURE OF THIS UPPER SYSTEM WILL LEAD TO WEAKENING LAPSE
RATES WITH TIME. WILL ADDRESS THE SEVERE THREAT BEYOND THE DAY5
PERIOD WHEN CONFIDENCE INCREASES REGARDING THE CONVECTIVE
OVERTURNING ACROSS THE HIGH PLAINS AND THE TIMING OF THE UPPER
TROUGH.

[wxman57]

This leads me to believe we have seen the last of temps below 40 degrees in Texas, south of a line from Austin to College Station.

http://www.cpc.ncep.noaa.gov/products/p ... day.01.gif

Yes, I believe that's true. A reason to celebrate! Winter is dead! Bring on the warmth of spring!

[srainhoutx]

Morning e-mail from Jeff:

What you see is what you get type of forecasting this week!



Near summer like pattern is in place across the region this morning with moist southerly flow at the low levels capped off by drier flow in the mid levels. This is producing a saturated near surface layer with a thick blanket of nighttime stratus clouds and some sea fog near the coast. Sea fog this morning has been on the lighter side as the winds have stayed up some overnight. Observations still show dewpoints exceeding nearshore water temperatures by up to 5 degrees so a sea fog bank could form at any time over the next few days.



With a fairly zonal flow aloft over the region there is little in the way of any kind of trigger to work on the moist unstable afternoon air mass. A few isolated to scattered showers will develop during the afternoon heat each day, but they will be fast moving and produce only .01 to .05 of an inch of rainfall.



Over the weekend, winds will increase even more as low pressure deepens in the plains. Will likely see south winds 15-25mph and gusty this weekend. The next potent upper level storm system will approach the region from the western US early next week and current models are showing some decent rainfall and severe weather possibilities with this system.



2012 Rainfall:

The year has started out on a very wet not with a total of 15.78 inches of rainfall at BUSH IAH through March 11, which is almost 8 inches above normal. This is in stark contrast to last year which to this same point in time had only recorded 5.83 inches of rainfall to March 11. The 15.78 inches of rainfall makes 2012 the 4th wettest start to a year in recorded history for the city. Last year it took until November 8th to get the same amount of rainfall in the city.



The City of Richmond in Fort Bend County has had 20.30 inches of rainfall so far making it the 2nd wettest start for that location only behind the 22.20 inches in 1992.

[wxman57]

Yes, the 12Z GFS does forecast more heavy rain next Wed/Thu. Two events. Lighter rain with frontal passage Tuesday. Front backs up and stalls overhead Wed/Thu with 3-5" rain across the city. At least it's mid week and not on the weekend this time.

Note that you'll need to add 3-4 degrees to the 2m raw temps on the graphic below:

[srainhoutx]

It appears the Euro wants to stall the boundary as well over SE TX in the Wednesday/Thursday timeframe, for what it's worth this far out.

[Ptarmigan]

It would be nice if West Texas got all the rain as they are in a drought.

[jasons2k]

I've had another 2.73" since yesterday. That brings my storm total up to 4.27" so far.

Better late than never...I had another .04" in showers Sunday afternoon. Grand total was 4.31"

[srainhoutx]

The guidance continues to advertise a wet and stormy pattern beginning Saturday night in far W TX and slowly migrating E on Sunday through Tuesday, It appears a deep Western trough will develop a cut off upper low and become slightly negative tilted Sunday into Monday creating a very heavy rainfall/severe weather event for W Central/Central TX and points N along a dry line.

A Pacific boundary will slowly crawl east on Monday night into Tuesday as the U/L deepens over Texas generating impressive storm totals and severe storms along and E of the dry line/boundary. There are some suggestions that areas in Central/N Central and E TX could see rainfall totals in the 5-8 inch range spreading over several days and some isolated 10 inch amounts + are not out of the question.

The bigger story with this event is the severe weather potential. The SPC has outlined areas in W Central TX on Day 4 and slightly further E on Day 5. As St. Patrick’s Day weekend progresses, increased low level Gulf flow and gusty Southerly winds will pump rich tropical moisture across Texas along with veering wind profiles as the U/L deepens will create an opportunity for rotating discrete super cells and a tornado thread is becoming a bit more clear for a large swath of the Southern Plains. Training cells will bring very heavy rainfall rates as they generally move from S to N along the trough axis/dry line as it creeps E over several days.

For us in SE TX, the better chances of rain and storms look to increase on Monday afternoon into Tuesday. Tuesday seems to be the better shot for severe weather here, but there is some uncertainty regarding just how quickly the trough axis and Pacific front will push into our area. Another fly in the ointment is some suggestion by the Euro that the boundary will stall somewhere over our area with heavy rains training from SW to NE along that boundary as the U/L meanders over N Central TX . That situation will need to be monitored and with guidance uncertainty and being 5-6 day out, expect ‘fine tuning’ in the longer range forecast in the days ahead.


ZCZC SPCSWOD48 ALL
ACUS48 KWNS 150834
SPC AC 150834

DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0334 AM CDT THU MAR 15 2012

VALID 181200Z - 231200Z

...DISCUSSION...

ECMWF/GFS CONTINUE TO SUGGEST A PROGRESSIVE...ALBEIT
SLOW-MOVING...UPPER TROUGH WILL TRANSLATE ACROSS THE WRN U.S. INTO
THE PLAINS DURING THE MEDIUM RANGE PERIOD. LEADING EDGE OF STRONGER
FLOW ALOFT SHOULD SPREAD ACROSS THE LEE TROUGH/DRY LINE FROM WRN NEB
INTO WEST TX BY SUNDAY EVENING. ANY STORMS THAT DEVELOP ALONG THIS
BOUNDARY COULD POTENTIALLY ORGANIZE AS 500MB FLOW INCREASES IN
EXCESS OF 50-70KT. BY DAY5 STRONGER FORCING WILL SPREAD DOWNSTREAM
AND THE GREATEST SEVERE THREAT IS EXPECTED TO EXTEND FROM THE KS/OK
BORDER...SWWD INTO THE HILL COUNTRY OF TX. BEYOND DAY5 THERE IS
CONSIDERABLE UNCERTAINTY REGARDING THE SPEED/MOVEMENT OF THE UPPER
TROUGH...AS WELL AS CONVECTIVE MODE.