May: Isolated Showers To End The Month

[jasons2k]

Looks like a meso low has formed in the squall line out west and is headed right towards me - I hope it holds together. I need more rain.

[Ptarmigan]

Last night storms woke me up. Quite a bit of thunder from them. Looks like tonight could be stormy and wet.

[spadilly]

rain just starting here in Spring Branch.

Listening to the thunder roll in. A good bit of lightning as well.

[jasons2k]

Well, a fresh line is forming now to my south and southeast, likely cutting off the infow to the storms to my west/nw. I may be caught in the middle of nothing again - geez why does this keep happening over and over again?

[jasons2k]

.39" here the last two days. I'm just speechless.

[srainhoutx]

1.12 inches here for the event. It's always interesting living in a large metropolitan area that the rainfall totals can be so dramatically different depending on what part of the area you live in.

[ticka1]

any more rain today - radar looks clear for se texas area

[srainhoutx]

any more rain today - radar looks clear for se texas area

It looks like the next chance of rain may be Wednesday as that pesky upper low in Mexico shears out and lift NE across Texas.

[srainhoutx]

Our neighbors in the Rio Grande Valley are benefiting from that pesky upper low/trough that is spinning stationary over Northern Mexico. The general upper flow is that of a zonal pattern from West to East across the Lower 48 during the coming week. There may be a bit of an upper ridge attempting to develop, but the models are also suggesting a bit of a trough return to the West late in the week that may bring rain and storm chances to portions of the Southern and Central Plains. I believe Katdaddy is out storm chasing this week. We wish him a s safe and successful trip.

[Ptarmigan]

Our neighbors in the Rio Grande Valley are benefiting from that pesky upper low/trough that is spinning stationary over Northern Mexico. The general upper flow is that of a zonal pattern from West to East across the Lower 48 during the coming week. There may be a bit of an upper ridge attempting to develop, but the models are also suggesting a bit of a trough return to the West late in the week that may bring rain and storm chances to portions of the Southern and Central Plains. I believe Katdaddy is out storm chasing this week. We wish him a s safe and successful trip.

05122013 14Z TX VIS latest.jpg

05122013 5dayfcst_wbg_conus.gif

Let the Rio Grande Valley have the rain as they are in a severe drought.

[srainhoutx]

Mid week rain and storm chances:


DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0226 AM CDT MON MAY 13 2013

VALID 151200Z - 161200Z

...NO SVR TSTM AREAS FORECAST...

...SYNOPSIS...
MINOR AMPLIFICATION OF THE UPPER PATTERN IS FORECAST OVER THE U.S.
WEDNESDAY/DAY 3...AS WEAK PHASING BETWEEN THE ERN CANADA SHORT-WAVE
TROUGH AND THE SECOND CROSSING THE S CENTRAL STATES IS
EXPECTED...WHILE FARTHER W AN ERN PACIFIC TROUGH APPROACHES THE W
COAST.

AT THE SURFACE...AN INCREASINGLY E-W COLD FRONT IS FORECAST TO LIE
ACROSS THE MIDWEST/OH VALLEY REGION AND WWD INTO KS THROUGH THE
PERIOD -- PROVIDING A FOCUS FOR AFTERNOON SHOWER AND THUNDERSTORM
DEVELOPMENT.

...PARTS OF ERN OH/PA/NRN WV/MD/NRN VA...
AS THE SURFACE COLD FRONT BECOMES INCREASINGLY W-E ORIENTED ACROSS
THE OH VALLEY REGION...EXPECT AFTERNOON SHOWERS AND THUNDERSTORMS TO
DEVELOP ALONG THE BOUNDARY FROM THE MID-ATLANTIC REGION WWD.
HOWEVER...IT APPEARS ATTM THAT MODEL DEPICTIONS OF BOUNDARY-LAYER
MOISTURE IS OVERDONE -- WITH MID 60S DEWPOINTS EVOLVING WITHIN THE
MODELS DAY 2 /TUESDAY/ INVOF THE MID MS/LOWER OH VALLEYS AND THEN
SPREADING EWD ACROSS THE OH VALLEY WEDNESDAY. AS A RESULT...THE
ACTUAL DEGREE OF DESTABILIZATION INVOF THE FRONT SHOULD REMAIN MUCH
LOWER THAN FORECAST -- THUS LIMITING SEVERE POTENTIAL. STILL...WITH
MODERATELY-STRONG FLOW ALOFT ACROSS THE REGION...WILL INTRODUCE 5%
SEVERE PROBABILITIES ATTM TO INDICATE POTENTIAL FOR ISOLATED
HAIL/DAMAGING WINDS DURING THE AFTERNOON/EVENING ACROSS THIS REGION.


...NRN AND CENTRAL TX AND VICINITY...
SCATTERED THUNDERSTORMS ARE FORECAST TO DEVELOP OVER THE SRN PLAINS
REGION AS A RELATIVELY WEAK UPPER TROUGH SHIFTS ACROSS THE AREA.
WITH DAYTIME HEATING COMBINING WITH MODEST MID-LEVEL
COOLING...MODERATE AFTERNOON DESTABILIZATION IS EXPECTED.
HOWEVER...WITH FLOW ALOFT PROGGED TO REMAIN RELATIVELY WEAK...STORMS
SHOULD REMAIN RELATIVELY DISORGANIZED -- SUPPORTIVE OF ONLY LOW /5%/
SEVERE PROBABILITY FORECAST ATTM. THREAT SHOULD REMAIN LARGELY
DIURNAL IN NATURE...DIMINISHING AFTER SUNSET.

..GOSS.. 05/13/2013

Weekend Storm Chances for Katdaddy and all the storm chasers converging across the Plains:

DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0344 AM CDT MON MAY 13 2013

VALID 161200Z - 211200Z

...DISCUSSION...
FOCUS FOR WIDESPREAD SEVERE WEATHER REMAINS ACROSS THE CENTRAL
PORTION OF THE U.S. FOR LATE THIS WEEK /FRI. THROUGH SUN. MAY
17-19/...AS A WRN U.S. TROUGH PROGRESSES EWD INTO THE PLAINS.

THE GFS AND ECMWF CONTINUE TO DIFFER WITH RESPECT TO THE EJECTION OF
THIS FEATURE...WITH DIFFERENCES BETWEEN THE MODELS GRADUALLY
INCREASING WITH TIME. STILL...A CONSISTENT SIGNAL FOR CENTRAL U.S.
SEVERE WEATHER HAS BEEN HINTED AT FOR SEVERAL DAYS...WITH CURRENT
INDICATIONS THAT THE GREATEST THREAT MAY EXIST BEGINNING DAY 6 /SAT.
5-18/. WHILE THE GFS HINTS AT SOME POTENTIAL FOR DAY 5/FRIDAY --
PARTICULARLY ACROSS THE NRN PLAINS VICINITY...THE SLOWER ECMWF
MAINTAINS RIDGING ACROSS THE PLAINS DAY 5. THUS...FOCUS THIS
FORECAST WILL BE ON DAY 6...WITH THE ZONE OF OVERLAP OF THE TWO
MODEL SOLUTIONS EXISTING ACROSS THE CENTRAL PLAINS VICINITY. WITH
STRONG INSTABILITY EXPECTED AND SHEAR LIKELY SUPPORTIVE OF
SUPERCELLS...LARGE HAIL AND DAMAGING WINDS WILL BE POSSIBLE...ALONG
WITH SOME TORNADO RISK.

ADDITIONAL SEVERE POTENTIAL WOULD LIKELY PERSIST -- THOUGH FARTHER E
-- FOR DAY 7/SUNDAY...BUT WITH DIFFERENCES IN MODEL SOLUTIONS
INCREASING AND WITH LIKELIHOOD FOR WIDESPREAD CONVECTION DAY 6
INFLUENCING DAY 7 CONVECTIVE POTENTIAL...WILL REFRAIN ATTM FROM ANY
AREAL ISSUANCE BEYOND DAY 6.

..GOSS.. 05/13/2013

[jasons2k]

In other words, if that's all the rain we're coming out of the gate from spring/winter and we're looking ahead to the sea breeze to keep us out of drought this summer, we're in deep trouble.

[David Paul]

We need and count on at least some rainfall from a tropical system each year to keep us out of drought and to keep lake Travis and the Edwards aquifer charged. Many have seen this...https://www.youtube.com/watch?v=LHSnKX0eVNQ It illustrates how little (closer to none) rainfall Texas got from last years tropical systems.

[Katdaddy]

One more mostly sunny day across SE TX before increasing rain chances from the next upper level disturbance. Higher chances for thunderstorms will be N of Houston metro area. Severe threat will remain low. Upcoming weekend looks partly sunny with mid 80s. Off to Wakita, OK to visit the Twister Museum dedicated to the movie Twister. A more active pattern still advertised by the weekend across the Midwest as ETT continues. Yesterday we were at Reed Timmer's house checking out the Dominator.

[Paul Robison]

Anyboy know if Wednesday's rains are likelyl to be a repeat of what we experienced on May 10, 2013. You know, with the hail, the lightning, and such?

[srainhoutx]

Morning e-mail from Jeff:

Upper level trough responsible for the heavy rains last week is now opening up and moving across TX this morning.

Overnight convection over NE MX is currently nearing our NW set of counties while additional convection south of Matagorda Bay is moving northward off the western Gulf. With the position of the trough axis near I-35 this morning moving eastward, would expect most rainfall coverage this morning west of I-45 trending to the I-45 corridor and eastward this afternoon. Moisture has greatly increased over the last 24 hours and PWS near Matagorda Bay are on the order of 1.7-1.9 inches. Expect to see fairly decent coverage of thunderstorms today. While moisture levels are fairly impressive, think any heavy rainfall threat will be isolated. There could be a few strong storms this afternoon, but any severe threat looks isolated.

Trough axis will be east of the area on Thursday with a building upper level high pressure cell out of MX. SE low level flow will continue and a “summer like” pattern will be established from Thursday into the weekend with lows near 70 and highs pushing near 90 under humid conditions. This is actually closer to normal for this time of year unlike the first two weeks of the month which have averaged anywhere from 5.0-6.5 degrees below normal.

[srainhoutx]

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0734 AM CDT WED MAY 15 2013

VALID 151300Z - 161200Z

...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON INTO TONIGHT FOR
PARTS OF TX...

...SYNOPSIS...

A SPLIT-FLOW PATTERN WILL PREVAIL OVER THE CONUS THROUGH THE D1
PERIOD WITH THE PRIMARY FEATURE OF INTEREST BEING A
SUBTROPICAL-BRANCH SHORT-WAVE TROUGH WHICH WILL EVOLVE INTO A CLOSED
LOW OVER THE SRN PLAINS TODAY. MEANWHILE...THE POLAR BRANCH OF
WESTERLIES WILL REMAIN MORE ENERGETIC WITH AN EMBEDDED SHORT-WAVE
TROUGH OVER THE UPPER GREAT LAKES AND ONTARIO ALSO EVOLVING INTO A
CLOSED MIDLEVEL CIRCULATION OVER QUEBEC LATER IN THE PERIOD.

IN THE LOW LEVELS...A SURFACE CYCLONE ASSOCIATED WITH THE LATTER
DISTURBANCE MENTIONED ABOVE WILL DEVELOP FROM LAKE HURON INTO THE
CANADIAN MARITIMES WHILE A TRAILING COLD FRONT SHIFTS EWD THROUGH
THE LOWER GREAT LAKES AND NEW ENGLAND. THIS BOUNDARY WILL STRETCH
WWD THROUGH THE OH...MID-MS...AND LOWER-MO VALLEYS BEFORE LINKING
WITH A LEE CYCLONE OVER THE CNTRL HIGH PLAINS. BY THIS
AFTERNOON...A DRYLINE OR LEE TROUGH WILL EXTEND FROM THE CNTRL
PLAINS LEE CYCLONE SWD TO A SECONDARY LOW DEVELOPING OVER WRN TX AND
INTO WRN PARTS OF THE EDWARDS PLATEAU.

...SRN PLAINS THIS AFTERNOON INTO TONIGHT...

LATEST MODEL GUIDANCE INDICATES A COMPLEX SITUATION TODAY WITH
MULTIPLE TSTM REGIMES FORECAST. ONGOING STORMS FROM THE TX HILL
COUNTY TO THE LOWER TX COAST APPEAR TO BE ASSOCIATED WITH A COUPLE
OF VORTICITY MAXIMA WHICH HAVE BEEN EMITTED FROM THE UPPER LOW OVER
NRN MEXICO. THIS ACTIVITY WILL CONTINUE EWD THIS MORNING AND LIKELY
REMAIN SUB-SEVERE. RENEWED TSTM DEVELOPMENT WILL BE POSSIBLE THIS
AFTERNOON IN THE WAKE OF THESE INITIAL STORMS /MAINLY E OF THE I-35
CORRIDOR/ WHERE INCREASED DCVA ATTENDANT TO THE UPPER TROUGH
INTERACTS WITH A MOIST...DESTABILIZING ENVIRONMENT. THE
JUXTAPOSITION OF MID AND HIGH-LEVEL WIND MAXIMA WITH A 30-35 KT LLJ
WILL RESULT IN SUFFICIENT VERTICAL SHEAR FOR ORGANIZED STORMS
INCLUDING SUPERCELLS CAPABLE OF A COUPLE OF TORNADOES AND DAMAGING
WINDS. THE PRIMARY UNCERTAINTY AT THIS JUNCTURE IS THE DEGREE OF
INSTABILITY THAT DEVELOPS OWING TO THE POTENTIAL FOR LINGERING
CLOUDS/PRECIPITATION. A SWD/SEWD EXTENSION OF THE CURRENT SLIGHT
RISK AREA MAY BECOME NECESSARY WITH THE NEXT UPDATE TO THE D1
OUTLOOK.

COMPARATIVELY HIGHER CONFIDENCE EXISTS IN THE DEVELOPMENT OF
SURFACE-BASED TSTMS LATER THIS AFTERNOON ALONG THE DRYLINE OVER NWRN
TX. HERE...STRONG HEATING WEST OF THE DRYLINE WILL COMBINE WITH A
VORTICITY MAXIMUM ROTATING AROUND THE PARENT UPPER LOW TO FOSTER
STORM DEVELOPMENT WITHIN A MODERATELY UNSTABLE AIR MASS WITH MLCAPE
OF 1000-2500 J/KG. FORECAST HODOGRAPHS EXHIBIT A PRONOUNCED VEERING
OF WINDS WITH HEIGHT AND 40-45 KT OF DEEP-LAYER SHEAR WHICH WILL
SUPPORT SUPERCELLS INITIALLY WITH A RISK FOR VERY LARGE HAIL AND
PERHAPS A BRIEF TORNADO. RELATIVELY WEAK ANVIL-LEVEL WINDS AND A
MODERATELY DEEP PBL WITH SIZABLE T-TD SPREADS WILL PROMOTE COLD POOL
GENERATION AND THE POTENTIAL FOR ORGANIZATION OF STORMS INTO A
SEWD-MOVING MCS /BOW ECHO -- AS SUGGESTED BY SOME
CONVECTION-ALLOWING MODEL GUIDANCE/. DAMAGING WIND GUSTS WOULD
BECOME THE PREDOMINANT HAZARD WITH THIS CONVECTIVE MODE TRANSITION.

FINALLY...STORM INITIATION ALONG THE SERRANIAS DEL BURRO RANGE IS
POSSIBLE THIS AFTERNOON WITHIN A MOIST...LOW-LEVEL UPSLOPE REGIME.
SUFFICIENT INSTABILITY AND VERTICAL SHEAR WILL EXIST FOR SUPERCELLS
WHICH COULD POTENTIALLY IMPACT PARTS OF THE EDWARDS PLATEAU AND THE
BRUSH COUNTRY WITH A RISK FOR HAIL AND DAMAGING WINDS THIS EVENING
INTO TONIGHT.

...UPPER-OH VALLEY INTO MID-ATLANTIC STATES THIS AFTERNOON AND
EVENING...

STRENGTHENING WLY FLOW IN THE 700-500-MB LAYER WILL PROMOTE THE EWD
ADVECTION OF AN EML ACROSS THE REGION TODAY...ALONG THE SRN FRINGE
OF THE PROGRESSIVE UPPER-LEVEL SYSTEM MOVING THROUGH ERN CANADA.
THESE LAPSE RATES WILL COINCIDE WITH A MOISTENING...PRE-FRONTAL
BOUNDARY LAYER TO YIELD AFTERNOON MLCAPE VALUES APPROACHING 500-750
J/KG. CAPPING AT THE BASE OF THE EML AND THE DISPLACEMENT OF
STRONGER MIDLEVEL HEIGHT FALLS/FORCING FOR ASCENT FROM THE SURFACE
FRONT CAST UNCERTAINTY ON SURFACE-BASED STORM DEVELOPMENT LATER
TODAY.

SHOULD SURFACE-BASED TSTMS DEVELOP AND BECOME SUSTAINED...THE
COMBINATION OF THE STEEP LAPSE RATES AND VERTICALLY VEERING WIND
PROFILES WITH 40-50+ KT OF NWLY DEEP-LAYER SHEAR WILL BE SUPPORTIVE
OF ORGANIZED STORM MODES WITH A RISK FOR DAMAGING WINDS AND SEVERE
HAIL. OTHERWISE...A MARGINAL HAIL THREAT WILL EXIST WITH ELEVATED
TSTMS MOVING ACROSS THE LOWER GREAT LAKES THIS MORNING.

...LOWER-MO/MID-MS VALLEYS THIS AFTERNOON AND EVENING...

THE NRN EXTENSION OF THE WARM CONVEYOR BELT ASSOCIATED WITH THE SRN
PLAINS UPPER LOW WILL ENHANCE THE NWD FLUX OF AN INCREASINGLY MOIST
BOUNDARY LAYER INTO THE REGION TODAY...ALONG AND SOUTH OF THE
STALLED SURFACE FRONT. THIS MOISTURE WILL COMBINE WITH DAYTIME
HEATING AND STEEP MIDLEVEL LAPSE RATES TO YIELD AFTERNOON MLCAPE
VALUES APPROACHING 1000-2000 J/KG. WHILE LARGE-SCALE FORCING WILL
REMAIN NEGLIGIBLE...LOW-LEVEL CONVERGENCE ALONG THE FRONT WILL BE
SUFFICIENT TO INITIATE WIDELY SCATTERED TSTMS LATER TODAY...THE MOST
INTENSE OF WHICH WILL BE CAPABLE OF LOCALLY STRONG WIND GUSTS AND
PERHAPS SOME HAIL. A MORE ROBUST SEVERE WEATHER THREAT WILL BE
LIMITED BY WEAK VERTICAL SHEAR.

..MEAD/MOSIER.. 05/15/2013

[Katdaddy]

On the way to SPS with ETT. Back home the severe threat looks low however some strong storms possible.

[srainhoutx]

In other words, if that's all the rain we're coming out of the gate from spring/winter and we're looking ahead to the sea breeze to keep us out of drought this summer, we're in deep trouble.

I'm not so sure that we'll have that to worry about that this summer. A Kelvin Wave is currently moving E from the Pacific and assisted in the development of EPAC Tropical Depression 1E. Some of that Pacific moisture may spread NE into Mexico and Texas early next week as the Western trough pulls abundant tropical moisture in our general direction. Water Vapor imagery is already showing a fire hose of tropical moisture spreading E from the Indian Ocean. As we get a bit closer to the end of May/first of June, there are indications that rather potent MJO pulse may arrive and the monsoonal trough will begin to lift north in the Caribbean. Time to keep an eye on Hurricane Central as we get a bit closer to the start of Tropical Season.

[Katdaddy]

NW TX now up to 5% for a tornado risk. Yes I am chasing with Extreme Tornado Tours.