Texas Spring 2013

[Ntxw]

That's interesting Ptarmigan. When I looked at 500mb charts for those dates I saw ridging either in Alaska or adjacent gulf of Alaska which signals -EPO. I know those months averaged +EPO but you can have certain weeks in the -EPO during those months. I don't have daily values for the epo so I am not certain on that aspect of official values.

Edit: Found those daily values for the EPO! Those cold snaps were indeed accompanied by very negative daily EPO values, especially December 1983 which was extreme.

ftp://ftp.cdc.noaa.gov/Public/gbates/te ... resent.txt

[Ntxw]

Well if the latest Euro is to be believed and to an extent the other globals, a possible freak cold core low could put a wet, cool, and damp period to start May. Also giving many of us 1-2 inches of rain on and off the next two weeks.

[weatherdude1108]

[Ntxw]

Latest CFSv2 long range guidance suggest May will end up below normal. Is the cooler spring hinting at a possible pleasant, relatively, summer? These patterns do like to go on for long stretches at a time.

[Tireman4]

1976 anyone? Hummmm

[Rgv20]

Still a cool 60F Cloudy with drizzle at my backyard

NWS in Brownsville hinting at possible severe weather sometime between Saturday and Monday...

.LONG TERM /SATURDAY THROUGH THURSDAY/...THE TREND THIS FORECAST
PACKAGE IS TO INCREASE POPS ANOTHER NOTCH AND KEEP TEMPERATURES
NEAR NORMAL. MEDIUM RANGE GLOBAL MODELS SHOW THE MID LEVEL PATTERN
TAKING ON A SPLIT FLOW PATTERN WITH WEST FLOW DEVELOPING OVER THE
SOUTHERN TIER STATES INCLUDING TEXAS. MODELS ARE DIRECTING
ATTENTION TO ONE ONE SHORTWAVE TROUGH BECOMING SOMEWHAT STATIONARY
OVER TEXAS CREATING A SHEAR ZONE TYPE PATTERN. TIME PERIOD FOR
BEST CHANCES LOOK TO BE FROM LATE SATURDAY ACROSS THE WESTERN
ZONES THEN COVERING THE ENTIRE CWA ON SUNDAY AND MONDAY WITH A
TAPERING OFF ON RAIN CHANCES TUESDAY. UNCERTAINTY RESIDES ON
WHERE THE SHEAR ZONE ENDS UP AND IF OUR CWA WILL BE IN THE BEST
AREA OF WEAK DIVERGENCE...IT COULD END UP FARTHER NORTH. MOISTURE
CONTENT WILL BE SUFFICIENT FOR SOME POCKETS OF MODERATE TO
POSSIBLE HEAVY RAIN UNDER ANY THUNDERSTORMS THAT DO DEVELOP.
SUFFICIENT CAPE AND SHEAR PROFILES TO SUPPORT ANY UPDRAFTS THAT
DEVELOP WHICH WILL SUPPORT HAIL FORMATION. THIS JUST IN TIME FOR
THE BEGINNING OF OUR PEAK SEVERE SEASON. SPC DOES NOT CURRENTLY
INDICATE SEVERE TSTMS IN THE 4-8 OUTLOOK SO WILL KEEP VIGILANCE ON
CURRENT PATTERN AND TRENDS.

TEMPERATURES TO MAINTAIN A NEAR NORMAL TREND. GFS TRENDED LOWER
SUNDAY AND MONDAY WITH INCREASE IN RAIN CHANCES. LOWERED SLIGHTLY
BUT DID NOT GO AS LOW AT THIS POINTS. IF ENOUGH SUN SHINE THROUGH
THE MOSTLY CLOUDY CONDITIONS THE HIGH LATE APRIL EARLY MAY SUN ANGLE
WILL WARM THINGS UP SUFFICIENTLY. STAY TUNED.

[weatherdude1108]

Very interesting discussion from the ewx office early this morning! Reminds me of the regular Texas Spring/early Summer Mexican Burro storms years ago as a kid in San Antonio that would come in overnight and wake me up.

"LONG TERM (SATURDAY NIGHT THROUGH THURSDAY)...
INCREASING CHANCES FOR SIGNIFICANT RAINS BEGIN SATURDAY NIGHT AS
THE FRONTAL BOUNDARY OR CONVECTIVE OUTFLOWS OFF THE FRONT BEGIN TO
SLIDE SOUTH INTO SOUTH CENTRAL TEXAS. THESE BOUNDARIES...COUPLED
WITH SIERRA DEL BURRO DEVELOPMENTS AND INCREASED DYNAMICS AND
INSTABILITY ALOFT WILL LEAD TO A GOOD CHANCE OF LATE EVENING AND
OVERNIGHT THUNDERSTORMS OVER MUCH OF SOUTH CENTRAL TEXAS.
ATMOSPHERIC PRECIPITABLE WATER AMOUNTS AVERAGING 1.3 TO 1.4 INCHES
SATURDAY NIGHT ARE ONE STANDARD DEVIATION HIGHER THAN WHAT IS
EXPECTED FOR THIS TIME OF YEAR...TRANSLATING TO EFFICIENT RAIN
PRODUCERS AND POTENTIALLY HEAVY RAIN AMOUNTS. IF A SIGNIFICANT
SURFACE BOUNDARY OR BOUNDARIES EXIST SATURDAY NIGHT AS EXPECTED...
WE COULD SEE RAINFALL AMOUNTS OF BETWEEN ISOLATED 2 TO 3 INCH IN
AMOUNTS IN THIS KIND OF PW (PRECIPITABLE WATER) ENVIRONMENT. A FEW
OF THE STORMS MAY APPROACH SEVERE LIMITS LATE EVENING THROUGH EARLY
OVERNIGHT WHEN LOW LEVEL FLOW AND SHEARS ARE BEST...THE MAIN THREAT
BEING FROM LARGE HAIL. THE CONTINUED PRESENCE OF SURFACE BOUNDARIES SUNDAY AND DYNAMICS ALOFT WILL RESULT IN A CONTINUED CHANCE OF
SHOWERS AND STORMS. HIGHS SUNDAY MID TO UPPER 70S HILLS TO LOW
80S ELSEWHERE. A REPEAT PERFORMANCE ALONG THE SIERRA DEL BURRO
MOUNTAINS OF NORTHERN MEXICO SUNDAY NIGHT COULD BRING ADDITIONAL
RAINS TO WESTERN AND SOUTH CENTRAL PORTIONS OF THE REGION. SOME
LINGERING SHOWERS AND STORMS FOR MONDAY AND MONDAY NIGHT AS SURFACE
BOUNDARIES DISSIPATE BUT DYNAMICS AND INSTABILITIES ALOFT REMAIN IN
DAYTIME HEATING. THERE ARE INDICATIONS OF CONTINUED BURRO MOUNTAIN
DEVELOPMENT OVERNIGHT MONDAY/TUESDAY MORNING AFFECTING MAINLY
SOUTHWEST PORTIONS. THE UPPER TROUGH AND INSTABILITY WILL PUSH
EAST OF THE REGION TUESDAY WITH PARTLY CLOUDY AND MILD CONDITIONS
AND A CHANCE OF SHOWERS AND THUNDERSTORMS MAINLY ALONG AND EAST
OF THE I-35 CORRIDOR. SHOWERS AND STORMS WILL END AS THE TROUGH
EXITS TO THE EAST TUESDAY EVENING."

[TeamPlayersBlue]

The 500MB chart looks crazy for this time of year. Well we wanted below normal temps all year! It's actually quite nice though, im not complaining.

[weatherdude1108]

I'm not complaining either! Neither is Bob Rose :

"These occasional blasts of cool air are expected to continue through at least the first half of May."

"Circulation around the low looks to pull additional Canadian air into Texas next weekend and even into the early part of the following week as well. While I’m not complaining, this cool pattern will be somewhat unusual for early May. In my opinion, the longer we can delay the heat of early summer, the better."

http://www.lcra.org/water/conditions/we ... olumn.html

[Rgv20]

Could be an interesting night!



Uploaded with ImageShack.us

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BROWNSVILLE TX
430 AM CDT SAT APR 27 2013

TXZ248>257-271700-
ZAPATA-JIM HOGG-BROOKS-KENEDY-STARR-HIDALGO-INLAND WILLACY-
INLAND CAMERON-COASTAL WILLACY-COASTAL CAMERON-
INCLUDING THE CITIES OF...ZAPATA...HEBBRONVILLE...FALFURRIAS...
SARITA...RIO GRANDE CITY...ROMA...MCALLEN...EDINBURG...PHARR...
MISSION...WESLACO...RAYMONDVILLE...BROWNSVILLE...HARLINGEN...
PORT MANSFIELD...PORT ISABEL...SOUTH PADRE ISLAND...
LAGUNA HEIGHTS...LAGUNA VISTA
430 AM CDT SAT APR 27 2013

...SEVERE THUNDERSTORMS POSSIBLE SATURDAY NIGHT...

ISOLATED TO SCATTERED SEVERE THUNDERSTORMS...FEATURING LARGE HAIL
AND DAMAGING WINDS...MAY AFFECT THE RIO GRANDE VALLEY AND ALL OF
DEEP SOUTH TEXAS SATURDAY NIGHT.

MOISTURE IN THE LOWER LEVELS OF THE ATMOSPHERE WILL COMBINE WITH
DAYTIME HEATING AND THE APPROACH OF A DISTURBANCE IN THE MIDDLE
LAYERS OF THE ATMOSPHERE TO PRODUCE SEVERE THUNDERSTORMS OVER THE
BIG BEND REGION AND NORTH TO NORTHEAST MEXICO THIS AFTERNOON AND
EVENING. THESE THUNDERSTORMS MAY THEN MOVE ACROSS THE RIO GRANDE
RIVER INTO PORTIONS OF THE RIO GRANDE VALLEY AND DEEP SOUTH TEXAS
TONIGHT...ESPECIALLY ALONG AND WEST OF THE HIGHWAY 281 CORRIDOR.

RESIDENTS OF THE RIO GRANDE VALLEY ARE ADVISED TO MONITOR THIS
DEVELOPING WEATHER SITUATION THROUGHOUT THE DAY TODAY THROUGH
NOAA ALL HAZARDS RADIO...LOCAL TELEVISION AND RADIO STATIONS...AND
THE WEBSITE OF YOUR NATIONAL WEATHER SERVICE OFFICE IN BROWNSVILLE
AT WEATHER.GOV/BROWNSVILLE.

$$

TOMASELLI

[Ntxw]

Euro is forecasting upper 30s and low 40s with rain for many areas of the northern half of Texas and snow in the panhandle and south plains, in May! Wow, now that would be highly unusual.

[Rgv20]

According to the 15zHRRR Thunderstorms out of Mexico should start entering South Texas by 6pm this evening.....Hopefully my area can get a good soaking out of this!



Uploaded with ImageShack.us

[vbhoutex]

Euro is forecasting upper 30s and low 40s with rain for many areas of the northern half of Texas and snow in the panhandle and south plains, in May! Wow, now that would be highly unusual.

Lows in the 40s on May 1 in SE TX? Are you kidding me? We may break low records again this Friday and the first two weeks sure don't look like May for SE TX!! Every time Spring tries to get started along comes another cold front. Are we going to have a Sprummer this year?

[Tireman4]

[/quote]Lows in the 40s on May 1 in SE TX? Are you kidding me? We may break low records again this Friday and the first two weeks sure don't look like May for SE TX!! Every time Spring tries to get started along comes another cold front. Are we going to have a Sprummer this year? [/quote]


I will take it sir. Thank you asking.

[Rgv20]

12zCMC and GFS Ensembles have all of Texas Temperatures well below normal from Tuesday April 30 thru Sunday May 5!


12zGFS Ensembles 5 day Mean Temperature Anomaly


Uploaded with ImageShack.us

12zCMC Ensembles 5 day Mean Temperature Anomaly


Uploaded with ImageShack.us

[vbhoutex]

They are probably right. We are expecting 42f Friday morning and 45f Saturday morning. Hello!!! That is in May!!!

[Rgv20]

Possible Severe Thunderstorm Watch for portions of Deep South Texas...



Uploaded with ImageShack.us

MESOSCALE DISCUSSION 0567
NWS STORM PREDICTION CENTER NORMAN OK
0643 PM CDT SAT APR 27 2013

AREAS AFFECTED...PORTIONS S TX.

CONCERNING...SEVERE THUNDERSTORM WATCH 142...

VALID 272343Z - 280145Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 142
CONTINUES.

SUMMARY...SVR POTENTIAL CONTINUES OVER MOST OF WW...POSSIBLE
EXCEPTION BEING PORTIONS NOW N OF SFC COLD FRONT FROM AUS AREA NWD
DEPENDING ON WHETHER STORM-SCALE PROCESSES FARTHER S CAN YIELD
LEFT-SPLITS MOVING INTO THIS AREA. AREAS ADJOINING SWRN BOUNDARY OF
WW...FROM COT SWD TO ZAPATA COUNTY...ALSO ARE BEING MONITORED FOR
POSSIBLE WW RELATED TO SVR WIND/HAIL POTENTIAL SHIFTING EWD FROM
MEX.

DISCUSSION...CLUSTERS OF STG-SVR TSTMS HAVE CONTINUED OVER GREATER
HOU METRO AREA AS WELL AS BETWEEN CLL-VCT...AND ALONG OLD
DIFFERENTIAL HEATING BOUNDARY OVER EDWARDS/REAL COUNTIES. LATTER
ACTIVITY IS IN MOST FAVORABLE MESOSCALE ENVIRONMENT FOR SUPERCELLS
AND DAMAGING HAIL...WITH FCST SOUNDINGS SUGGESTING 45-50 KT
EFFECTIVE SHEAR MAGNITUDES AND 2500 J/KG MLCAPE.
HOWEVER...STORM-SCALE/OUTFLOW PROCESSES MAY YIELD MESSY ECHO
STRUCTURES. ADDITIONAL DEVELOPMENT IS POSSIBLE ALONG THEIR
OUTFLOWS...AS WELL AS THOSE OF TSTMS ELSEWHERE IN WW. THOUGH STILL
AT LEAST MRGLLY FAVORABLE FOR SVR...BOTH BUOYANCY AND DEEP SHEAR
WILL CONTINUE TO BE WEAKER WITH EWD EXTENT...SUGGESTING SOMEWHAT
LESS-ORGANIZED SVR THREAT IN SE TX DESPITE GREATER CURRENT TSTM
COVERAGE. MAIN CONCERN OVER MID-UPPER TX COASTAL PLAIN WILL BE
DAMAGING DOWNDRAFTS RELATED TO PRECIP LOADING...GIVEN 1.75-INCH PW
AND WEAKER WINDS ALOFT...WITH ISOLATED LARGE HAIL STILL POSSIBLE.

OVERALL INCREASE IN COVERAGE OF SHOWERS AND TSTMS HAS BEEN EVIDENT
DURING LAST HOUR OVER AREAS W OF RIO GRANDE...BETWEEN ZAPATA COUNTY
AND DRT. GENERALLY CONFLUENT AND UPSLOPE FLOW INTO THIS REGION
YIELDS ENHANCEMENT TO STORM-RELATIVE INFLOW...AS WELL AS INCREASING
MOISTURE FOR ANY ACTIVITY THAT CAN GET WELL-ROOTED IN BOUNDARY
LAYER. COUNTERBALANCING FACTOR IS EML...WHICH OFFERS STEEP MIDLEVEL
LAPSE RATES BUT ALSO 50-100 J/KG MLCINH ESTIMATED E OF MEX MTNS NEAR
RIO GRANDE. ANY CONVECTION THAT CAN BECOME SUFFICIENTLY CLUSTERED
TO DEVELOP COLD POOL COULD PROVIDE SUFFICIENT FORCED ASCENT TO
OVERCOME THAT CINH AND SUSTAIN SVR RISK FROM MEX INTO PORTIONS DEEP
S TX S OF PRESENT WW.

..EDWARDS.. 04/27/2013


ATTN...WFO...LCH...SHV...HGX...FWD...CRP...EWX...BRO...

LAT...LON 28180018 29300081 29720159 29960173 30210151 30259942
30549764 31439568 31159483 30369458 29659444 28749583
28809718 28649854 27989839 27379851 26419906 26799922
27049946 27589952 27819990 28110003 28180018

[Ntxw]

JMA and Ukmet sees the cold too. It's incredible considering our sun angle is equivalent to that in late July and early August. Deep cutoff low in the middle of the country with snow in areas of the southern plains, I know it has happened before in the past but not since I can remember.

[weatherdude1108]

They are probably right. We are expecting 42f Friday morning and 45f Saturday morning. Hello!!! That is in May!!!

I'm not complaining. Making up for the 80s we saw in January and February.

[Ntxw]

Nice warm days the next few. Then the bottom falls and we go back to winter! And then guess what? You got it, long range models suggest yet ANOTHER unusually late strong cold front. Rinse and repeat the second winter.

The persistent warm pool in the central Pacific better of the last 2 years has made a new home off the west coast. This persistent area has created a semi-permanent high pressure dome over the EPAC for weeks, thus our chill. No signs of it breaking down anytime soon.