March 2010- In Like A Lamb, Out Like A Lion?

[wxdata]

Tuesday afternoon and evening bears watching for the potential for some isolated strong storms.

Could be. Both the 12z GFS and NAM do put a marginally unstable atmosphere over SE TX by Tuesday afternoon.

Lifted Index;
Cape

[svrwx0503]

18z models are in and it is interesting to note that they show less moisture across the region Tuesday and more on Wednesday with a slightly better wind field and instability coming into play. SPC has out-looked the possibility of a severe threat Wednesday as seen in the extended discussion below.

...DISCUSSION...
A PROGRESSIVE SOUTHERN STREAM AIDED BY A STRONG SUBTROPICAL JET WILL
INITIALLY PREVAIL IN THE OUTLOOK PERIOD...WITH THE INITIAL FOCUS ON
AN EMBEDDED SHORTWAVE TROUGH THAT APPEARS LIKELY TO CROSS NORTH
TX/ARKLATEX VICINITY TO THE TN RIVER VALLEY ON DAY 4/WEDNESDAY.
WHILE CONSIDERABLE VARIABILITY STILL EXISTS WITH THE TIMING OF THIS
SHORTWAVE TROUGH...GIVEN FAVORABLE WIND FIELDS JUXTAPOSED WITH A
RELATIVELY MOIST/POTENTIALLY UNSTABLE AIRMASS...IT DOES SEEM THAT AN
APPRECIABLE SEVERE RISK MAY EXIST ON DAY 4/WEDNESDAY ACROSS EAST TX
TO THE NEIGHBORING ARKLATEX VICINITY/PERHAPS LOWER MS RIVER VALLEY.
HOWEVER...AFOREMENTIONED VARIABILITY/LIMITED PREDICTABILITY
PRECLUDES 30% DAY 1 EQUIVALENT PROBABILITIES. SOME SEVERE THREAT MAY
EXIST DAY 5/THURSDAY ACROSS THE CENTRAL GULF COAST/SOUTHEAST
STATES...BUT CONSIDERABLE UNCERTAINTY EXISTS AND WIDESPREAD SEVERE
STORMS SEEM UNLIKELY AT THIS JUNCTURE.

[wxdata]

18z GFS data shows Houston would be on the western edge of the best threat Wednesday afternoon (marginal still)

Lifted Index:

[srainhoutx]

DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0235 AM CST MON MAR 08 2010

VALID 101200Z - 111200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS SOUTHEAST OK/ARKLATEX TO
LOWER MS RIVER VALLEY...

...EAST TX/SOUTHEAST OK TO LOWER MS RIVER VALLEY...
IN ASSOCIATION WITH A POTENT UPPER TROUGH THAT IS FORECAST TO
ADVANCE NORTHEASTWARD FROM THE SOUTHERN HIGH PLAINS TO THE OZARKS
VICINITY...IT APPEARS AN APPRECIABLE SEVERE POTENTIAL WILL EXIST
ACROSS PORTIONS OF EAST TX/SOUTHEAST OK TO THE ARKLATEX/LOWER MS
RIVER VALLEY ON WEDNESDAY. WITH A RELATIVELY MOIST AIRMASS REMAINING
IN PLACE ACROSS THE ARKLATEX/LOWER MS VALLEY IN THE WAKE OF
TODAYS/TUESDAYS UPPER TROUGH OVER THE MIDWEST...INCREASING LARGE
SCALE FORCING FOR ASCENT/STRENGTHENING WIND FIELDS ALOFT SHOULD
SUPPORT INCREASING SEVERE TSTM DEVELOPMENT DURING THE MID/LATE
AFTERNOON HOURS OF WEDNESDAY INITIALLY ACROSS THE ARKLATEX VICINITY.
SUFFICIENT LOW LEVEL MOISTURE/INSTABILITY AND STRONG/VEERING FLOW
THROUGH THE LOW/MID TROPOSPHERE WILL SUPPORT AN INITIAL MODE OF
SUPERCELLS WITH SEVERE HAIL/TORNADO POTENTIAL. BUT GIVEN THE DEGREE
OF LARGE SCALE FORCING/HEIGHT FALLS...IT SEEMS LIKELY THAT STORMS
SHOULD EVOLVE INTO A QUASI-LINEAR CONVECTIVE SYSTEM BY EARLY
EVENING...WITH A CONTINUED DAMAGING WIND/TORNADO RISK QUICKLY
SPREADING EAST-NORTHEASTWARD TOWARD THE LOWER MS RIVER VALLEY.
ADDITIONAL BOUTS OF SEVERE TSTMS WILL ALSO BE POSSIBLE FARTHER
SOUTHEAST ALONG THE CENTRAL GULF COAST VICINITY...PERHAPS MAINLY
WEDNESDAY NIGHT.

...EASTERN OK/FAR SOUTHEAST KS TO OZARKS/LOWER MO RIVER VALLEY...
OTHER LOWER TOPPED SEVERE STORMS WILL POSSIBLE MAINLY ACROSS
PORTIONS OF EASTERN OK/NORTHERN AR/SOUTHERN MO IN CLOSER PROXIMITY
TO THE NORTHEAST ADVANCING UPPER SYSTEM. BOUNDARY LAYER MOISTURE
/50S F/ WILL BE MORE LIMITED ACROSS THIS REGION...BUT IT APPEARS
LIKELY THAT SURFACE BASED TSTM DEVELOPMENT WILL OCCUR AHEAD OF THE
COMPACT UPPER TROUGH AND ALONG/SOUTH OF A STALLED
SOUTHWEST-NORTHEAST ORIENTED FRONT. WHILE LAPSE RATES WILL BE STEEP
AND VERTICAL SHEAR WILL BE STRONG...UNCERTAINTY REGARDING THE DEGREE
OF MOISTURE/INSTABILITY PRECLUDES SLIGHT RISK CALIBER SEVERE
PROBABILITIES AT THIS TIME.

..GUYER.. 03/08/2010

HGX thinking this may be the best shot at severe weather "locally' this week...

DISCUSSION...
A SERIES OF UPPER LEVEL DISTURBANCES WILL RESULT IN UNSETTLED WEATHER
ACROSS SOUTHEAST TEXAS FOR THE FIRST HALF OF THE WEEK. THE FIRST LOW
ACROSS CENTRAL ARIZONA EARLY THIS MORNING WILL BE NEAR THE TX-OK PANHANDLE
AREA AROUND SUNSET TONIGHT. OUR AREA WILL SEE INCREASING SHOWER AND
ISOLATED THUNDER COVERAGE AS THE DAY PROGRESSES. RAINFALL TOTALS OF
1/2 TO 1 INCH WITH ISOLATED 1 TO 2 INCH AMOUNTS ARE ANTICIPATED. DECENT
DYNAMICS REMAIN IN PLACE TONIGHT FOR ADDITIONAL SHOWER AND ISOLATED
THUNDERSTORM DEVELOPMENT AS ENERGY FROM THE LOW MOVES ACROSS THE AREA.
THE COMBINATION OF DAYTIME HEATING AND A WEAK SURFACE BOUNDARY IN THE
AREA MIGHT ALLOW FOR SOME ADDITIONAL SHOWER/THUNDERSTORM FORMATION ON
TUESDAY MAINLY ACROSS OUR EAST AND SOUTHEAST COUNTIES. THE LAST CHANCE
OF STORMS COMES ON WEDNESDAY WHEN THE FINAL UPPER LEVEL LOW RACES EASTWARD
ACROSS THE STATE. THIS EVENT COULD END UP BEING OUR BEST SHOT OF SEEING
SOME SEVERE STORMS THIS WEEK WITH PRETTY GOOD DYNAMICS ANTICIPATED.
AS FOR HIGH TEMPERATURES THROUGH MIDWEEK...THE AREA CAN EXPECT A WARM UP
ON TUESDAY AND WEDNESDAY WITH READINGS REACHING THE LOWER TO MID 70S.
WE DRY OUT AFTER WEDNESDAY AS A DEEP UPPER LOW BECOMES ESTABLISHED ACROSS
THE EASTERN U.S. STATES. EXPECT LOWS GENERALLY IN THE 40S AND HIGHS
GENERALLY IN THE 60S WITH MOSTLY CLEAR TO PARTLY CLOUDY SKIES FOR
THE END OF THE WEEK AND THROUGH NEXT WEEKEND. 42

[srainhoutx]

Regarding today from the SPC...

...PARTS OF CNTRL AND SRN/SE TX...
MODEST DESTABILIZATION WILL OCCUR THROUGH THIS EVE OVER CNTRL TX
AHEAD OF AFOREMENTIONED COLD FRONT AS SFC DEWPOINTS RISE INTO THE
LWR 60S F. HOWEVER...LARGE SCALE FORCING FOR ASCENT WILL REMAIN
WEAK AS STRONGEST DPVA WITH AZ/NM UPR SYS TRACKS N OF THE REGION.

CONVECTION/SCTD WAA TSTMS LIKELY WILL INCREASE IN COVERAGE OVER THE
REGION THROUGH THE DAY. ADDITIONAL...POSSIBLY STRONGER STORMS MAY
CONTINUE TO DEVELOP ON WRN FRINGES OF EXISTING ACTIVITY THROUGH
TONIGHT AS FRONT CONTINUES EWD BENEATH MODERATE TO STRONG WSW
MID/UPR LVL FLOW. MODEST INSTABILITY AND WEAK LARGE-SCALE ASCENT
SHOULD LIMIT OVERALL SVR POTENTIAL DESPITE PRESENCE OF DEEP SHEAR
FAVORABLE FOR SUSTAINED STORMS/SUPERCELLS. ALTHOUGH WDLY SCTD
HAIL/WIND EVENTS MAY OCCUR...ATTM THREAT STILL APPEARS TOO LIMITED
TO WARRANT SLIGHT RISK.

http://radar.weather.gov/Conus/southplains_loop.php

[srainhoutx]

HGX Update...looks wet today/tonight...

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
957 AM CST MON MAR 8 2010

.DISCUSSION...
GPSMET DATA SHOWS A HIGHLY MOIST AIRMASS IN PLACE ACROSS SE TX
THIS MORNING WITH PWS IN THE 1.3-1.5 INCH RANGE. SFC DEWPOINTS
HAVE CLIMBED INTO THE UPPER 50S/LOWER 60S. 850 MB ANALYSIS SHOWS
THAT DEWPOINTS HAVE CLIMBED TO 10+C ACROSS OUR WRN ZONES. RADAR
SHOWS SHOWERS HAVE FILLED IN ACROSS THE SRN HALF OF THE AREA
DURING THE LAST HOUR. 00Z 4KM NMM-WRF AND LATEST GFS RUN INDICATE
A VERY ACTIVE AFTERNOON ACROSS THE AREA AS AXIS OF LOW LEVEL JET
AND DEEPEST MOISTURE SHIFT EAST ACROSS THE CWA. WARM ADVECTION
WILL CONTINUE TO RESULT IN WIDESPREAD SHOWERS. HAVE UPPED POPS FOR
TODAY AREA WIDE. THE CLOUDS AND RAIN WILL KEEP MAX TEMPS IN THE
60S. GFS BUFR SOUNDINGS SHOW STRONG LOW LEVEL SHEAR BUT NO SFC
INSTABILITY AND LIS ABOVE ZERO THIS AFTN. SOME ELEVATED THUNDER
WILL OCCUR BUT NO SURFACE BASED STORMS OR SEVERE WEATHER THREAT
FOR TODAY.

THE 4KM NMM-WRF INDICATES A SECOND ROUND OF CONVECTION OCCURRING
LATE TONIGHT/TUESDAY AS UPPER DIFFLUENCE IS MAXIMIZED THIS PERIOD
AND SFC DRYLINE APPROACHES FROM THE WEST. HAVE UPPED POPS ACROSS
THE AREA THIS PERIOD. MODELS INDICATE A GREATER POTENTIAL FOR SFC
BASED STORMS THIS PERIOD WITH THE POSSIBILITY OF ISOLATED SEVERE.
WILL TAKE MORE OF A LOOK AT THIS ON THE AFTERNOON PACKAGE.

[wxman57]

That sounding is pretty dry. Without much moisture aloft, it'll be hard to get storms. Our best shot of any storms will be this afternoon and this evening. After that, dry air moves in. Severe chances look to be very minimal.

[wxdata]

Weather turning a bit nasty over by Abilene with a severe thunderstorm warning...

[wxman57]

That sounding is pretty dry. Without much moisture aloft, it'll be hard to get storms. Our best shot of any storms will be this afternoon and this evening. After that, dry air moves in. Severe chances look to be very minimal.

NAM does develop some showers Wednesday.

http://www.nco.ncep.noaa.gov/pmb/nwprod ... f_054s.gif

Yeah, there appears to be some passing moisture around mid day, but not much at 12Z or 00Z.

[wxdata]

Severe threat growing north and west of here:

MESOSCALE DISCUSSION 0160
NWS STORM PREDICTION CENTER NORMAN OK
0142 PM CST MON MAR 08 2010

AREAS AFFECTED...NORTH AND CNTRL TX...SW OK

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 081942Z - 082115Z

AN ISOLATED SEVERE THREAT WILL LIKELY CONTINUE EWD ACROSS NORTH TX
AND SW OK THIS AFTERNOON. THE STRONGER CELL ELEMENTS IN THE LINE
WILL HAVE POTENTIAL FOR DAMAGING WIND GUSTS AND HAIL. WW ISSUANCE
REMAINS POSSIBLE ACROSS THE MCD AREA.

A WELL-DEVELOPED LINE OF STRONG THUNDERSTORMS NEAR WICHITA FALLS SWD
TO AROUND BRADY IS LOCATED ALONG THE EAST EDGE OF AN AXIS OF
MODERATE INSTABILITY WITH SBCAPE VALUES AROUND 1000 J/KG. THE LINE
IS BEING SUPPORTED BY A 30 TO 40 KT LOW-LEVEL JET JUST TO THE EAST
AND IS LOCATED JUST AHEAD OF A BAND OF STRONG LARGE-SCALE ASCENT
ASSOCIATED WITH THE UPPER-LEVEL SYSTEM TO THE NORTHWEST. THESE TWO
FACTORS WILL LIKELY HELP MAINTAIN THE LINE EWD ACROSS THE
DALLAS...FORT WORTH METROPLEX LATE THIS AFTERNOON. THE WSR-88D VWP
FROM FORT WORTH CURRENTLY SHOWS 40 TO 45 KT OF FLOW JUST ABOVE THE
SFC. THIS COMBINED WITH A FORWARD SPEED OF THE LINE AT 35 KT WILL
RESULT IN A POTENTIAL FOR DAMAGING WIND GUSTS. FORECAST SOUNDINGS
AROUND FORT WORTH ALSO SHOW STEEP MID-LEVEL LAPSE RATES AND COLD AIR
ALOFT WHICH COMBINED WITH STRONG DEEP LAYER SHEAR SHOULD BE
SUFFICIENT FOR HAIL WITH THE STRONGER UPDRAFTS.

[srainhoutx]

The dryline raises an eyebrow. Playing havoc with our outdoor schedule for mid week. ~sigh~ HGX afternoon disco paints an interesting picture regarding Tuesday and Wednesday...

SFC DRYLINE SHOULD BE OVER OUR NW ZONES TUE MORNING WITH DIFFLUENT
FLOW ALOFT AND MOIST AIRMASS RESULTING IN SCATTERED TSRA ACROSS
THE EAST IN THE MORNING HOURS. DRYLINE WILL LIKELY STALL NEAR OR
JUST WEST OF THE US 59 CORRIDOR TUESDAY. SUNSHINE AND HEATING WILL
ALLOW AIRMASS EAST OF THE BOUNDARY TO BECOME MODERATELY UNSTABLE
TUE AFTN. GFS SHOWS A SWATH OF 1000-1500 J/KG SFC-BASED CAPE OVER
THE EASTERN HALF OF THE CWA BY 18Z TUESDAY. WILL KEEP CHANCE POPS
GOING OVER THE EAST TUE AFTN ANTICIPATING SOME REDEVELOPMENT.
INSTABILITY/SHEAR WILL SUPPORT A SMALL SEVERE WEATHER POTENTIAL
TUESDAY. EXPECT TSRA TO DISSIPATE BY SUNSET. DRYLINE TO RETREAT
BACK WEST TUE NIGHT WITH STRATUS/FOG DEVELOPMENT LIKELY OVER MUCH
OF THE AREA. SEA FOG IS ALSO A POSSIBILITY OVER THE BAYS. MODELS
SHOW THE NEXT SIGNIFICANT SHORTWAVE NOW OVER NORTHERN CALIFORNIA
QUICKLY PASSING THROUGH THE SRN PLAINS WEDNESDAY. ALTHOUGH THE
MODELS HAVE TRENDED FURTHER NORTH WITH THIS FEATURE...DYNAMICS
STILL LOOK VERY IMPRESSIVE WEDNESDAY WITH SE TX IN THE LEFT FRONT
QUAD OF A 160 KT 300 MB JET. STEEP LAPSE RATES WILL ALLOW AIRMASS
TO DESTABILIZE AGAIN WEDNESDAY WITH CAPES 1000-1500 J/KG. A QUICK
ROUND OF CONVECTIVE DEVELOPMENT EXPECTED DURING THE DAY WEDNESDAY
AND HAVE MAINTAINED 40/50 POPS AREA WIDE. SOUNDINGS AGAIN SUPPORT
A LOW SEVERE WEATHER THREAT AND SPC HAS CLIPPED OUR NE ZONES IN
SLIGHT RISK. PACIFIC COLD FRONT WILL CROSS THE AREA LATE WEDNESDAY
FOLLOWED BY RAPID CLEARING AND DRY/MILD CONDITIONS WED
NIGHT/THURSDAY. A STRONGER COLD FRONT WILL CROSS THE AREA THU
NIGHT. WILL SEE ANOTHER EXTENDED PERIOD OF BELOW NORMAL TEMPS
BEGINNING THU NIGHT AND LASTING THROUGH EARLY NEXT WEEK AS
NORTHERLY FLOW ALOFT SETS UP REINFORCING COOL AIRMASS OVER THE
AREA. DRY CONDITIONS ARE EXPECTED...HOWEVER WILL SEE SOME WRAP-
AROUND STRATOCU AFFECT ESPECIALLY THE NE ZONES FRIDAY AND
SATURDAY.

[wxdata]

Slight bowing of squall line south of Ft. Worth. Reports of winds 40-50 mph and penny sized hail

[wxdata]

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
341 PM CST MON MAR 8 2010


.DAYS TWO AND THREE...TUESDAY AND WEDNESDAY

A PAIR OF UPPER LEVEL DISTURBANCES WILL COMBINE WITH DAYTIME HEATING
TO GENERATE SCATTERED SHOWERS AND THUNDERSTORMS ALONG AND AHEAD OF
A SURFACE DRYLINE DURING THE DAY TUESDAY AND AGAIN ON WEDNESDAY. THE
POTENTIAL EXISTS FOR A FEW STRONG TO SEVERE THUNDERSTORMS...ESPECIALLY
OVER THE EASTERN HALF OF SOUTHEAST TEXAS.

[wxdata]

MESOSCALE DISCUSSION 0162
NWS STORM PREDICTION CENTER NORMAN OK
0518 PM CST MON MAR 08 2010

AREAS AFFECTED...CENTRAL-E CENTRAL TX

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 082318Z - 090045Z

LINE OF THUNDERSTORMS MOVING EWD ACROSS PORTIONS OF CENTRAL-E
CENTRAL TX WILL BE CAPABLE OF PRODUCING AN ISOLATED SEVERE WIND
GUST...BUT A WW APPEARS UNLIKELY AT THIS TIME.

A LINE OF THUNDERSTORMS AT 23Z EXTENDED FROM 30 SSE OF DAL TO 30 SE
OF JCT...AND WAS MOVING ENE AT AROUND 30 KT. THE NRN PORTION OF THIS
LINE IS ENCOUNTERING COOLER SURFACE TEMPERATURES AND A MORE STABLE
BOUNDARY LAYER...WHILE SLY LOW LEVEL FLOW CONTINUES TO MAINTAIN A
FEED OF MOIST /LOW TO MID 60S DEWPOINTS/ MODERATELY UNSTABLE AIR
/MLCAPE VALUES UP TO 1000 J PER KG/ INTO THE SRN HALF OF THE LINE.
AN INVERSION IN THE 850-600 MB LAYER IS DEPICTED IN RUC FORECAST
SOUNDINGS...WHICH IS LEADING TO WEAK MID LEVEL LAPSE RATES...AND
SHOULD MITIGATE THE POTENTIAL FOR LARGE HAIL. HOWEVER...VWP DATA
INDICATES STRONG LOW LEVEL VERTICAL WIND SHEAR PRESENT ALONG AND
AHEAD OF THE LINE...WITH STRENGTHENING WLY MOMENTUM SPREADING EWD
ACROSS THE REGION. THESE WIND PROFILES WILL CONTINUE TO FAVOR BOWING
SEGMENTS...WITH ONE CELL DURING THE LAST HR MOVING E FROM LAMPASAS
COUNTY TO BELL COUNTY DISPLAYING A MESOVORTEX STRUCTURE...SUGGESTIVE
OF ENHANCED POTENTIAL FOR DAMAGING WIND GUSTS. MODEL GUIDANCE
INDICATES THAT THE SRN HALF OF THE LINE WILL EVENTUALLY EXPERIENCE A
MORE STABLE BOUNDARY LAYER DURING THE EVENING...AND WILL ALSO BECOME
INCREASINGLY ORIENTED PARALLEL TO UPPER LEVEL WIND
FIELDS...RESULTING IN LOWER POTENTIAL FOR BOWING. THUS...THESE
TRENDS ARE EXPECTED TO LEAD TO A DECREASING THREAT FOR SEVERE WIND
GUSTS DURING THE 00-03Z TIME PERIOD.

[srainhoutx]

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0641 PM CST MON MAR 08 2010

VALID 090100Z - 091200Z

...NO SVR TSTM AREAS FORECAST...

...W CENTRAL OK...
STORMS CONTINUE ACROSS W CENTRAL OK ATTM....WITHIN THE DRY SLOT
IMMEDIATELY AHEAD OF THE UPPER LOW CENTER WHERE MODEST INSTABILITY
/ON THE ORDER OF A FEW HUNDRED J/KG MIXED-LAYER CAPE/ PERSISTS.
WHILE A LONG-LIVED TORNADO HAS BEEN OBSERVED OVER THE PAST 1-2
HOURS...THE PARENT STORM CONTINUES TO WEAKEN. THIS TREND IS
EXPECTED TO CONTINUE DUE TO BOTH THE ONSET OF BOUNDARY-LAYER
COOLING/STABILIZATION...AND THE CONTINUED NEWD SHIFT OF THE
CONVECTION AWAY FROM THE WRN OK INSTABILITY AXIS. WILL MAINTAIN LOW
SEVERE PROBABILITIES ATTM...BUT EXPECT MAIN THREAT LINGERING OVER
THE NEXT COUPLE OF HOURS TO BE MARGINALLY-SEVERE HAIL.

...CENTRAL AND ERN TX...
DISORGANIZED LINE OF THUNDERSTORMS CONTINUES FROM SERN OK/NERN TX
SWWD INTO THE HILL COUNTRY...WHERE MODEST INSTABILITY -- MIXED-LAYER
CAPE AOB 500 J/KG -- PERSISTS ALONG AND AHEAD OF THE SURFACE
TROUGH/DRYLINE. WHILE A LOCALLY-DAMAGING GUST OR MARGINALLY-SEVERE
HAIL EVENT REMAINS POSSIBLE...ANY THREAT SHOULD DIMINISH OVERNIGHT
AS BOUNDARY LAYER STABILIZES AND STORMS CONTINUE SHIFTING E OF THE
PRIMARY AXIS OF LINGERING INSTABILITY.

..GOSS.. 03/09/2010

[sleetstorm]

Outback on 1960 near Champions.


And a Hawaiian shirt.

I went to Tia Maria's here in Baytown on 1711 Garth Rd. with my parents, my youngest sister, and my aunt, and received some money from some of my relatives.

[wxdata]

MESOSCALE DISCUSSION 0163
NWS STORM PREDICTION CENTER NORMAN OK
1201 AM CST TUE MAR 09 2010

AREAS AFFECTED...S CNTRL TX THROUGH SE OKLAHOMA AND THE ARKLATEX

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 090601Z - 090730Z

A WW IS NOT CURRENTLY ANTICIPATED...BUT TRENDS ARE BEING MONITORED
FOR THE POSSIBILITY OF AN INCREASING SEVERE THREAT.

RECENT INCREASE IN THUNDERSTORM ACTIVITY NEAR THE DRY LINE ACROSS
TEXAS...FROM DEL RIO NORTHEASTWARD INTO AREAS NORTHEAST OF THE
DALLAS/FORT WORTH AREA...APPEARS TO BE AIDED BY THE LEADING EDGE OF
STRONGER MID-LEVEL LEVEL COOLING ASSOCIATED WITH APPROACHING LARGE
UPPER TROUGH. FORCING ASSOCIATED WITH A SHORT WAVE IMPULSE PIVOTING
THROUGH THE BASE OF THE TROUGH MAY ALSO BE A SUPPORTING FACTOR. AND
THIS MAY MAINTAIN CONVECTIVE DEVELOPMENT THROUGH THE 08-09Z TIME
FRAME AS IT SHIFTS ACROSS NORTH CENTRAL TEXAS TOWARD THE OZARK
PLATEAU AND ARKLATEX. SMALL LOW-LEVEL HODOGRAPHS AND WEAK CAPE ARE
EXPECTED TO LIMIT THE SEVERE POTENTIAL...BUT A FEW STORMS COULD
PRODUCE LOCALIZED WIND GUSTS AND SOME HAIL THAT COULD AT LEAST
APPROACH SEVERE LIMITS.

[weatherguy425]

I'm heading out the door but perhaps a new topic?

SHORTWAVE TROF TRAVELING DOWN ACROSS CALIFORNIA THIS MORNING TO
HEAD DUE EAST OVER THE DESERT SW AND LIFT OUT IN THIS CURRENT
LOW`S WAKE OVER OK WEDNESDAY. CONSIDERING ALL OF THE ABOVE AND THE
MODERATE CHANCE OF THE INITIATION OF A WESTERN TX DRY LINE MOVING
OUR WAY...WED POPS WILL INCREASE. LAY ON TOP OF THIS NEARING DRY
LINE...RESIDUAL BOUNDARIES IN A MODESTLY MOIST ENVIRONMENT...AND A
STRONG CENTRAL TX 190 KT JET STREAK PUNCHING INTO THE REGION AND
YOU HAVE ALL OF THE SIGNS POINTING TO HIGH CHANCE POPS INCREASING
INTO LIKELY THROUGH THE DAY. IF ALL OF THESE ELEMENTS COME INTO
PHASE...WE WILL BE DEALING WITH SEVERE WEATHER COME WEDNESDAY
AFTERNOON. TOO EARLY TO GET SPECIFIC IN ZONES...BUT WILL HIGHLIGHT
THIS POSSIBLE SEVERE THREAT IN THIS MORNING`S HWO. ALAS...SPRING
HAS SPRUNG!

[srainhoutx]

I'm heading out the door but perhaps a new topic?

SHORTWAVE TROF TRAVELING DOWN ACROSS CALIFORNIA THIS MORNING TO
HEAD DUE EAST OVER THE DESERT SW AND LIFT OUT IN THIS CURRENT
LOW`S WAKE OVER OK WEDNESDAY. CONSIDERING ALL OF THE ABOVE AND THE
MODERATE CHANCE OF THE INITIATION OF A WESTERN TX DRY LINE MOVING
OUR WAY...WED POPS WILL INCREASE. LAY ON TOP OF THIS NEARING DRY
LINE...RESIDUAL BOUNDARIES IN A MODESTLY MOIST ENVIRONMENT...AND A
STRONG CENTRAL TX 190 KT JET STREAK PUNCHING INTO THE REGION AND
YOU HAVE ALL OF THE SIGNS POINTING TO HIGH CHANCE POPS INCREASING
INTO LIKELY THROUGH THE DAY. IF ALL OF THESE ELEMENTS COME INTO
PHASE...WE WILL BE DEALING WITH SEVERE WEATHER COME WEDNESDAY
AFTERNOON. TOO EARLY TO GET SPECIFIC IN ZONES...BUT WILL HIGHLIGHT
THIS POSSIBLE SEVERE THREAT IN THIS MORNING`S HWO. ALAS...SPRING
HAS SPRUNG!

Let's keep things in this Topic for now. A bigger severe threat would probably warrant a new Topic. With that said, the SPC Update this morning seems to keep the best chances confined to our eastern areas...we shall see...

...SE TX/LWR MS VLY...
MOISTURE WILL CONTINUE TO SLOWLY INCREASE IN MODERATE SWLY LOW-LVL
FLOW ALONG AND AHEAD OF LEAD COLD FRONT/CONFLUENCE ZONE OVER AR/LA
AND E TX TODAY/TONIGHT AS ASSOCIATED UPR SYSTEM RETREATS NEWD.
LINGERING BAND OF 40-50 KT WSWLY MID LVL FLOW...AND CONTINUING
PRESENCE OF STRONG /120 KT/ HI-LVL SUB-TROPICAL JET...WILL MAINTAIN
WIND PROFILES SUPPORT OF SUSTAINED STORMS/SUPERCELLS.

LOW TO MID-LVL LAPSE RATES...WHILE NOT PARTICULARLY STEEP...WILL BE
SUFFICIENT FOR VIGOROUS UPDRAFTS GIVEN GRADUALLY INCREASING MOISTURE
/PW AOA 1.25 INCHES/ AND PRESENCE OF PERSISTENT LOW-LVL CONVERGENCE.

WITH SOURCE OF LARGE SCALE FORCING FOR ASCENT MOVING NE INTO
MO...DEEP ASCENT ACROSS REGION MOST DIRECTLY MAY BE TIED TO PASSING
LOW AMPLITUDE DISTURBANCES IN SUB-TROPICAL JET. ONE SUCH FEATURE
APPEARS TO BE OVER S TX ATTM...AND ANOTHER MAY AFFECT LA/SE TX EARLY
WED. EXPECTED WEAKENING OF SFC FRONT/CONFLUENCE AXIS SUGGESTS THAT
LOW-LVL FORCING FOR ASCENT WILL REMAIN WEAK. BOUNDARIES FROM
CURRENT WAA CONVECTION/STORMS WILL...HOWEVER... ALSO BE PRESENT TO
ENHANCE LOW-LVL UPLIFT.

IN SUMMARY...SETUP APPEARS TO BE ONE OF A LOW CONDITIONAL RISK FOR
SUPERCELLS. GIVEN EXPECTED WIND/THERMODYNAMIC ENVIRONMENT...BOTH
SVR HAIL AND TORNADOES WOULD BE POSSIBLE...BUT OVERALL STORM
COVERAGE SHOULD REMAIN ISOLD. WHILE ANY SVR THREAT LIKELY WOULD BE
GREATEST THIS AFTN AND EARLY TONIGHT...A LIMITED THREAT COULD
PERSIST THROUGH WED MORNING AS AFOREMENTIONED SUB-TROPICAL IMPULSE
APPROACHES REGION.

[srainhoutx]

HPC Morning Prelim paints a wet pattern for TX early next week...

PRELIMINARY EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
744 AM EST TUE MAR 09 2010

VALID 12Z SAT MAR 13 2010 - 12Z TUE MAR 16 2010

...FLOODING REMAINS A THREAT ACROSS NEW YORK/NEW ENGLAND FROM THIS
WEEKEND INTO EARLY NEXT WEEK...

TELECONNECTIONS WITH A SLOWLY RETROGRADING POSITIVE ANOMALY IN
CENTRAL CANADA CONTINUES TO FAVOR CLOSED CYCLONES PROGRESSING
UNDER ITS BASE IN THE MID TO UPPER 30S LATITUDE...WHICH FITS THE
IDEA OF THE GUIDANCE WITH THE FIRST SYSTEM MOVING THROUGH THE
MID-ATLANTIC AND OFFSHORE THE NORTHEAST...BUT IS NORTH OF WHAT THE
GUIDANCE IS SUGGESTING WITH THE SYSTEM MOVING THROUGH THE
SOUTHWEST INTO THE SOUTHERN PLAINS. WITH MORE OF THE
DETERMINISTIC GUIDANCE ABOARD THE CLOSED CYCLONE BANDWAGON...AND
THE PREFERENCE FOR THIS PATTERN OVER THE PAST SEVERAL
WEEKS...CONFIDENCE IS INCREASING IN THIS SOLUTION. THE 06Z GFS IS
THE ONLY PIECE OF GUIDANCE NOT TO HAVE A CLOSED SYSTEM MOVING
THROUGH THE SOUTHWEST...WHICH IT ACCOMPLISHES BY MOVING A CLOSED
CYCLONE THROUGH THE NORTHERN PLAINS INSTEAD...WHICH IS SUPPORTED
BY NONE OF THE 00Z MULTI-MODEL ENSEMBLE GUIDANCE. THEREFORE...THE
PRESSURES ARE BASED ON A 00Z ECMWF/00Z ECMWF ENSEMBLE MEAN
COMPROMISE WHICH DEALS WITH THE REMAINING DETAIL DIFFERENCES. THE
ECMWF ENSEMBLE MEAN WAS CHOSEN AS IT CONTINUES TO SHOW
STRONGER/MORE DEFINED FEATURES IN ITS PRESSURE PATTERN THAN THE
00Z GEFS OR 00Z BIAS-CORRECTED NAEFS MEANS. THIS SOLUTION
MAINTAINS REASONABLE CONTINUITY.

WEATHER-WISE...THE LARGE SYSTEM MOVING THROUGH THE EAST IS
EXPECTED TO SPREAD MODERATE TO HEAVY RAINS TO THE MID-ATLANTIC AND
NEW ENGLAND STATES BETWEEN THE 13TH AND 15TH. WHILE THE SNOW
COVER IS NEARLY GONE ACROSS LOWER ELEVATIONS OF THE SOUTHERN AND
CENTRAL MID-ATLANTIC STATES FROM THE SNOW STORMS OF OVER ONE MONTH
AGO...THE SAME CANNOT BE SAID FOR NEW YORK... NEW ENGLAND...AND
THE SPINE OF THE APPALACHIANS WHICH HAVE EXPERIENCED MORE RECENT
SNOWS. SINCE THE SYSTEM IS WARM...EVEN IF THE PRECIPITATION
EXPECTED WAS LESS THAN ADVERTISED... SNOW MELT WOULD ADD TO THE
FLOOD THREAT FROM THIS WEEKEND INTO EARLY NEXT WEEK ACROSS NEW
YORK AND NEW ENGLAND. OUT WEST...THE HEAVIEST PRECIPITATION IS
SAVED FOR THE 13TH ACROSS WASHINGTON STATE...WITH THE THREAT OF
ADDITIONAL HEAVY RAINFALL ON THE 16TH AND 17TH. THE CLOSED
CYCLONE MOVING THROUGH THE SOUTHWEST AND SOUTHERN PLAINS SHOULD
SPREAD LIGHT TO MODERATE PRECIPITATION ALONG ITS PATH UNTIL IT
TAPS GULF MOISTURE ON THE 15TH WHICH COULD BRING HEAVY RAINS TO
TEXAS ON THE 15TH AND 16TH.
ROTH