April: Sunny and Dry Heading Into May

[BlueJay]

Srain, will we have a lovely weekend or will we need jacket and an umbrella?

Warmer weather appears likely as we push 80 for high temperatures Saturday into Sunday. Late Sunday may offer a slight chance of streamer showers into Tuesday before a weak front nears the Coast. It looks like a nice and warm Easter Weekend is ahead for those outdoor activities.

Thanks! I'm looking forward to enjoying it. I hope everyone has a great weekend!

[srainhoutx]

A signicant pattern change is lurking as we finally transition away from shorter wave lengths to that of a more typical Spring Time pattern with longer wave lengths and daily onshore flow and increasing deep tropical moisture. Once we get beyond Tuesday when a weak frontal boundary pulls up stationary across our Region and lifts N, it appears tropical moisture from the Western Caribbean will replace the Continental air and transition to a more typical Texas pattern with scattered showers and daytime storms.

We are seeing signs of long fetch moisture flow off the Gulf returning for the first time since last Fall as this pattern transition begins. The Plains Severe Season has been delayed, but it appears that increasing chances of severe weather will begin as we end April and begin May. Happy Easter everyone. And remember Tropical Season is just about a month and a half away.

[jasons2k]

The Euro has us right on the edge of decent rains in about a week. Yesterday, it showed a healthy 2-3" IMBY only to wipe it clean in the next run. I suspect it will be inconsistent for a few days.

[unome]

once upon a time I remember May as a rainy month, but it's been a while, at least in northern Harris...


http://www.srh.noaa.gov/hgx/?n=climate_ ... ls_summary

http://www.srh.noaa.gov/hgx/?n=climate_ ... ls_summary

http://www.srh.noaa.gov/hgx/?n=climate_ ... ls_summary

http://www.srh.noaa.gov/hgx/?n=climate_ ... ls_summary


hopefully this year it is, as our water rates just went up to cover the cost of converting to surface water, a needed action, just wish our HOA was more lenient about landscaping with less water-needy plants and grasses

[Andrew]

keep an eye on tomorrow, especially for our NW counties. SPC has already put most of central Texas in a slight risk and some of the higher resolution models are indicating that a line/cluster could form and push through the area tomorrow evening.

[srainhoutx]

I'm not sure the model have a clue with a major pattern shift expected later in the week with a big negative tilted trough developing out West. If the guidance is close to being correct there may be a severe weather episode across the Central US and unusually cold weather entering the Western 2/3rds of the Lower 48 and possibly well below normal temperatures across the Southern Plain and Texas early next week. We will see.

[srainhoutx]

Morning Update from Jeff:

Mid and upper level low pressure system over OK this morning will help to promote a slight chance of showers and thunderstorms this evening into Tuesday.

Weak frontal boundary is moving southward this morning and is located over NW TX with thunderstorms ongoing over S OK. Early visible images show decent breaks in the overcast over NC TX and surface heating should commence along and ahead of the frontal boundary over the next few hours. Moisture return over SE TX has been meager over the last 72 hours with dewpoints only in the 50’s and low 60’s as surface high pressure over the Gulf is preventing rich moisture advection into the region. Should see enough heating by mid afternoon for isolated to scattered strong to severe thunderstorms develop along the frontal boundary over N and C TX and this is shown well on nearly all of the short term guidance yielding fairly high confidence in storm development. Models then weaken the activity as it approaches SE TX by mid evening, but would not be surprised to see a few storms reach the College Station to Livingston area.

Weak frontal boundary will move into the area on Tuesday and possibly act as enough of a focus for shower and thunderstorm development. Current thinking is that activity will be widely scattered at best with capping to overcome and still poor moisture quality. Best chances may end up being near the coast…but this is likely only in the 20-30% coverage range.

Rest of the week will be dry and warm with lows in the 60’s and highs in the 80’s with slowly increasing humidity values. Long range guidance continues to show a strong cold front for late April standards toward the start of next week possibly pushing the area back into the 40’s and 50’s for lows and with our next “best” chance of rainfall.

Day 1 (today) Severe Weather Outlook:

04212014 Jeff image001.jpg

[jasons2k]

Poof!

[Andrew]

Looks like the NW part of the state could have an active day on Wednesday. A lot of the higher resolution models indicate that the dry line could produce a couple of discrete cells before clustering/turning linear. Locally, things should remain quite as the bulk of the energy stays north and comes through during the overnight hours. As we head further into the weekend things could get interesting for a lot of the central plains (and even closer to home) as the synoptic pattern continues its transition to a more active and progressive state. Early indications show impressive parameters aligning across the Oklahoma/TX Panhandle on Saturday, but phasing of Wednesday's wave and the resulting return flow from the gulf are giving models trouble. The 00z suite show better model consensus, but some of the finer details (such as the LLJ progression) still have a wide variety in solutions. Either way, this weekend's severe event has the POTENTIAL for being one of the more potent events in recent history. I suspect a day 4-8 extended outlook from the SPC will be issued tonight with the better model consensus.

" DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1219 AM CDT TUE APR 22 2014

VALID 231200Z - 241200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE CENTRAL AND SOUTHERN
PLAINS...

...SUMMARY...
SCATTERED SEVERE THUNDERSTORMS ARE EXPECTED TO DEVELOP WEDNESDAY
AFTERNOON ACROSS THE HIGH PLAINS FROM NORTHWEST TEXAS TO NORTHERN
NEBRASKA. LARGE HAIL AND DAMAGING WINDS CAN BE EXPECTED WITH THIS
ACTIVITY.

...CENTRAL AND SOUTHERN PLAINS...

MULTIFACETED TROUGH WILL MIGRATE ACROSS THE ROCKIES WEDNESDAY WITH
PRIMARY CORRIDOR OF HEIGHT FALLS EXPECTED TO FOCUS OVER THE
NRN/CNTRL HIGH PLAINS THROUGH EARLY EVENING. HOWEVER...NAM
CONTINUES TO SUGGEST A LOW-AMPLITUDE SHORT-WAVE TROUGH WILL EJECT
FROM THE BASE OF THE PROGRESSIVE TROUGH ACROSS THE SRN HIGH PLAINS
INTO SWRN KS/TX PANHANDLE AFTER 21Z. 50KT+ 500MB SPEED MAX IS
FORECAST TO SPREAD ACROSS THE DRYLINE INTO NWRN OK BY 24/00Z
ENHANCING ENVIRONMENTAL SHEAR FOR SUSTAINING ORGANIZED ROTATING
UPDRAFTS.

LEE TROUGH WILL BE DISLODGED OFF THE HIGHER TERRAIN INTO WRN
KS...SWD INTO ERN TRANS PECOS OF TX AS STRONGER FLOW SPREADS ACROSS
THIS REGION...AIDED BY STRONG HEATING. WHILE ABSOLUTE MOISTURE
CONTENT IS NOT EXPECTED TO BE THAT GREAT...PW VALUES SHOULD RISE TO
AROUND ONE INCH JUST EAST OF THE DRYLINE WHERE SFC DEW POINTS HOLD
IN THE 50S. AS SFC TEMPERATURES WARM TO NEAR 80F SFC PARCELS SHOULD
FREELY CONVECT WITHIN A THERMODYNAMIC ENVIRONMENT CHARACTERIZED BY
ROUGHLY 1500-2000 J/KG SBCAPE. INITIALLY THIS ACTIVITY SHOULD BE
FAIRLY HIGH-BASED BUT LIKELY SUPERCELLULAR IN NATURE AS SUBSTANTIAL
SFC-6KM BULK SHEAR WILL EXIST ACROSS THIS REGION. LATEST THINKING
IS SCT SUPERCELLS...CAPABLE OF PRODUCING VERY LARGE HAIL...SHOULD
EMERGE DURING THE LATE AFTERNOON FROM THE ERN TX PANHANDLE...NWD
INTO WRN KS. SCT-NUMEROUS THUNDERSTORMS...WITH EMBEDDED
SUPERCELLS...ARE EXPECTED TO DEVELOP ALONG SURGING COLD FRONT ACROSS
NEB. THIS ACTIVITY MAY EVOLVE INTO A SQUALL LINE DURING THE EVENING
AS STRONG LLJ FOCUSES ACROSS ERN KS INTO SWRN IA.

EWD EXTENT OF THIS DIURNALLY INITIATED CONVECTION MAY ULTIMATELY
SPREAD TO NEAR I-35 CORRIDOR ACROSS OK/KS/NWRN MO/IA BY THE END OF
THE PERIOD.

..DARROW.. 04/22/2014"

[srainhoutx]

A negative tilted trough in late April tends to spell trouble across the Southern Plains extending E into the Mid Mississippi/Tennessee Valley Regions. The Storm Prediction Center is ramping up the wording for the potential of a multi day severe weather event and what I find a bit unusual are the 850's 0C line dropping right down into SE Texas and The Gulf Coast. That suggests we may see some rather chilly temperatures for this time of year in the wake of that severe weather episode.

DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0345 AM CDT TUE APR 22 2014

VALID 251200Z - 301200Z

...DISCUSSION...
...SIGNIFICANT MULTI-DAY SEVERE EVENT EXPECTED ACROSS THE SOUTH
CENTRAL U.S. SATURDAY AND SUNDAY...STRONG TORNADOES ARE POSSIBLE...

22/00Z ECMWF IS EXHIBITING REASONABLE RUN-TO-RUN CONSISTENCY OVER
THE LAST FEW DAYS WITH THE GFS NOW TRENDING TOWARD ECMWF SOLUTIONS.
THIS FORECAST IS HEAVILY WEIGHTED TOWARD THE ECMWF.

EARLIER CONCERNS REGARDING A POLAR FRONT UNDERCUTTING STRONG SWLY
FLOW ALOFT OVER THE SRN PLAINS ARE LESSENING. WHILE UPPER BLOCK
OVER CNTRL CANADA WILL ULTIMATELY FORCE A DOMINANT SFC ANTICYCLONE
INTO THE MIDDLE OF THE CONUS...IT APPEARS THE LEADING EDGE OF THIS
AIR MASS SHOULD STRUGGLE TO ADVANCE MUCH SOUTH OF I-70 OVER KS/MO
THIS WEEKEND.

STRONG MID-LEVEL SPEED MAX IS FORECAST TO DIG SEWD INTO THE LOWER CO
RIVER VALLEY SATURDAY WITH UPPER DIFLUENCE EXPECTED ACROSS THE
PLAINS AS FAR SOUTH AS WEST TX AT 27/00Z. THIS EVOLUTION WILL ALLOW
SUBSTANTIAL MOISTURE TO ADVANCE POLEWARD ACROSS THE SRN PLAINS WHERE
PW VALUES SHOULD EASILY APPROACH 1.25 INCHES AS SFC DEW POINTS CLIMB
THROUGH THE MID-UPPER 60S ACROSS A BROAD WARM SECTOR. LATEST
THINKING IS MODERATE-EXTREME INSTABILITY SHOULD DEVELOP ALONG ERN
PLUME OF STEEP LAPSE RATES FROM WCNTRL TX...NWD INTO SCNTRL KS
SATURDAY WHERE MUCAPE COULD APPROACH 4000 J/KG. IF THERMODYNAMIC
ENVIRONMENT EVOLVES AS LATEST GUIDANCE SUGGESTS THEN POTENTIALLY
SIGNIFICANT SUPERCELL DEVELOPMENT WITH VERY LARGE HAIL AND TORNADOES
CAN BE EXPECTED. CONVECTION SHOULD INITIATE ALONG DRYLINE FROM SWRN
TX...NWD INTO WRN KS SATURDAY THEN REDEVELOP AGAIN SUNDAY FROM SERN
KS...SWD INTO CNTRL TX AS MID-LEVEL SPEED MAX EJECTS INTO THE SRN
PLAINS. SEVERE TSTMS SHOULD SPREAD INTO THE MS VALLEY BY EARLY
MONDAY. ORGANIZED SEVERE MAY CONTINUE INTO THE DAY7 PERIOD BUT
SUBSTANTIAL CONVECTION DURING THE DAY5-6 TIME FRAME COULD
POTENTIALLY DISRUPT THERMODYNAMIC ENVIRONMENT...THUS CONFIDENCE IS
NOT AS HIGH.

..DARROW.. 04/22/2014

[BlueJay]

On April 22, 1970 Earth Day was established.

Happy Earth Day Everyone!

[srainhoutx]

Morning Update from Jeff:

Very little change to the increasingly warm and dry pattern in place.

Weak boundary is laying across the area this morning separating fog to the south with mainly clear skies to the north. Muggy dewpoints in the mid to upper 60’s along the coast are poised to start creeping northward today as winds return to the south. Could see fog again the next few mornings if winds are not too strong in the overnight hours.

Next upper level storm system looks to arrive into the southern plains this weekend. Forecast parameters are coming together for what could be a significant outbreak of severe weather including long tracked tornadoes across much of north TX into OK. At this time this looks to be one of the more impressive setups this severe weather season so far for the southern plains. As has been the case for the past few months SE TX will lie at the southern end of this outbreak with the potential for a few strong storms to approach or affect our northern counties Sunday afternoon/evening. Will need to keep an eye on how things begin to evolve starting Friday to see if there is better potential for severe weather to affect our northern counties. Onshore flow today-Sunday will push dewpoints into the 70’s by the weekend with lows in the 70’s and highs in the mid to upper 80’s making it feel more like early summer.

A strong late season cold front will move southward Sunday night and cross the area Monday. Showers and thunderstorms look at least possible with this boundary, but as has been the case this spring rain chances have tended to “dry up” as the event nears. Timing of the frontal boundary in the morning hours makes it less likely that severe weather would accompany the front.

Air mass behind this boundary will be cold for late April standards with lows into the 50’s and possibly even the 40’s early to middle next week.

[Texaspirate11]

There sure is a colorful cacophony of cyclogenesis chaos on the wx maps. Hope Houston can stay out of it.
Although we do need some rain.

[BlueJay]

This interesting article from khou.com discusses Wichita Falls, Texas investing in cloud seeding to make it rain, sort of.
Although this technology has been around for awhile, it seems very sci-fi to me and would hate to see this mechanism replacing a good old fashioned rain shower or "FUNderstorm" as Ed says.

Come on and Rain-dag nab it!!!

http://www.khou.com/news/texas-news/Des ... 53661.html

[Katdaddy]

Another warm day ahead with a few isolated storms N and NE of Houston metro.

[BlueJay]

This is exciting! It looks like rain on the radar. I did feel some microscopic drops on my arm a few moments ago.

[BlueJay]

We are experiencing some rockin' thunder and driplets of rain at the moment.

[jasons2k]

Thunder and lightning here, I was totally shocked when I heard thunder, wondering "what?"

[BlueJay]

Poof! No measurable precip but fun while it lasted.

[TxLady]

Well, dang it, just enough thunder/lightning and sprinkles to run me off my outside house painting project. There's still enough dark clouds around to keep me off the ladder.