January Weather Discussion: Slight Chance Severe Storms

[vci_guy2003]

We won't hit the mid thirties tonight lol. Steady temps near 40

[srainhoutx]

HPC says toss out the GFS and Canadian as too progressive (fast) and trust the Euro (and UKMET to some extent)...regarding the pattern and pressures…support for a cutoff low to our W gains momentum...


PRELIMINARY EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
155 AM EST FRI JAN 14 2011

VALID 12Z TUE JAN 18 2011 - 12Z FRI JAN 21 2011


THE PRELIMINARY FRONTS AND PRESSURES FOR DAYS 3 THROUGH 7 ARE
BASED ON THE 00Z/14 ECMWF. THE LATEST DETERMINISTIC ECMWF HAS
ROBUST SUPPORT FROM BOTH THE 12Z/13 ECENS MEAN AND THE 00Z/14
UKMET FROM COAST TO COAST FOR MUCH OF THE MEDIUM RANGE. THE GFS
AND GEM GLOBAL ARE OUT OF SYNC WITH THE STRONG EUROPEAN CENTRE
CLUSTER WITH THE HANDLING OF THE MAJOR SHORTWAVES AFFECTING THE
NATION THIS FORECAST PERIOD...WITH THE GFS NOT EVEN WELL
CORRELATED WITH THE 00Z/14 GEFS MEAN. THE ECMWF HAS BEEN
VERIFYING STRONGLY ON AVERAGE THIS COLD SEASON WITH ITS SURFACE
PRESSURES...PARTICULARLY DAYS 6 AND 7. THE UPCOMING PATTERN WILL
BE HIGHLIGHTED BY SOME OF THE COLDEST AIR OF THE SEASON THUS FAR
FOR PORTIONS OF THE GREAT LAKES AND NORTHEAST...WITH LOW
THICKNESSES COINCIDING WITH HIGH SURFACE PRESSURES.


CISCO

San Angelo concurs and mentions the flip of the 06Z GFS...

HE MAIN ITEMS OF FOCUS NEXT WEEK POSSIBILITY OF FAIRLY STRONG
COLD FRONTAL PASSAGES LATE MONDAY NIGHT AND AGAIN THURSDAY MORNING.
A GOOD WARMUP IS EXPECTED ON MONDAY WITH WEST-SOUTHWEST LOW-LEVEL
FLOW AND 850 MB TEMPERATURES CLIMBING ABOVE 10 DEGREES C. AFTER
THE COLD FRONTAL PASSAGE HIGHS ON TUESDAY SHOULD BE AROUND 12-16
DEGREES COOLER THAN MONDAY. THE 00Z GFS AND ECMWF CONTINUE SO HAVE
DIFFERENCES WITH THE PATTERN LATER NEXT WEEK. THE 06Z GFS NOW
DEVELOPS AN UPPER LOW SOUTHWEST OF CALIFORNIA ON THURSDAY...WHICH
IT DID NOT SHOW ON ITS 00Z RUN. THE 06Z GFS LOOKS MORE SIMILAR TO
THE 00Z ECMWF WITH THIS FEATURE. GFS IS ALSO FASTER AND NOT AS
STRONG WITH THE COLD FRONT...BRINGING IT THROUGH OUR AREA EARLY
THURSDAY MORNING. THE ECMWF HAS THE FRONTAL PASSAGE DURING THE DAY
THURSDAY...HAS STRONGER COLD AIR ADVECTION AND IS SLOWER WITH THE
MODIFICATION ON FRIDAY. MODELS HAVE NOT BEEN SHOWING VERY MUCH
SKILL ON DAYS 6 AND 7. AT THIS TIME...LEANING TOWARD THE ECMWF
SOLUTION WHICH IS FAVORED BY HPC.

[Mr. T]

Yesterday's high of 39 at IAH makes it the first 30 degree day of the year. Hooray and so forth

[wxman57]

Good news today, folks! My long-range forecaster/coworker now thinks that a major cold outbreak that could bring a very hard freeze to Houston is looking less likely next week. I agree. Though the models did hint at such a front a few days ago, we haven't seen much in the last 6-8 model runs to support such an event. The cold air could very well just spill southeastward toward the Great Lakes and northeast U.S. and we may only get a small piece of it. We won't be sure of that for another 3 days or so.

[C2G]

That's great news wxman.
Now, bring on an early Spring and I'll really be impressed.

[srainhoutx]

The new Euro weeklies suggest the cold will stay around for another month. Early Spring Canceled. Sorry.

[srainhoutx]

Now looking toward the weekend, it is looking damp and all that cold air is building across the Northern US...

SHORT RANGE FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
337 AM EST FRI JAN 14 2011

VALID 12Z FRI JAN 14 2011 - 12Z SUN JAN 16 2011

MOISTURE WILL GENERALLY BE LIMITED EAST OF THE ROCKIES ENTERING
THE HOLIDAY WEEKEND AS THE WINDS OFF THE GULF OF MEXICO WILL FOR
THE MOST PART BE OFFSHORE. THE EXCEPTION WILL BE ACROSS EXTREME
SOUTH TEXAS WHERE THE SURFACE FLOW WILL SHIFT TO THE MORE
FAVORABLE SOUTH-SOUTHEASTERLY DIRECTION. AS AN IMPULSE DROPS
THROUGH NORTHERN MEXICO ON SATURDAY...IT WILL BEGIN TO INTERACT
WITH THE ENHANCED MOISTURE PLUME TO AFFORD AN AREA OF RAIN SHOWERS
WHICH WILL GRADUALLY SHIFT NORTH AND EAST IN TIME.

FARTHER TO THE NORTH...AN ACTIVE JET STREAM WILL ALLOW A PAIR OF
DISTURBANCES TO PROJECT EASTWARD ACROSS THE NORTHERN TIER STATES.
THE FIRST OF THESE SYSTEMS IS CURRENTLY PUSHING INTO UPPER OHIO
RIVER VALLEY BEFORE PUSHING OFFSHORE BY MIDDAY FRIDAY. AS THE
ENERGY PUSHES TOWARD THE EAST...IT WILL BEGIN ENCOUNTERING A
STRONG SURFACE RIDGE WHICH WILL PUT A HALT TO ANY EXTENSIVE REGION
OF PRECIPITATION. FARTHER UPSTREAM...THE SECOND OF THESE FRONTAL
SYSTEMS WILL BE MUCH STRONGER THAN THE FORMER. AN AMPLIFYING UPPER
TROUGH WILL AFFECT THE GREAT LAKES REGION LATE FRIDAY/EARLY
SATURDAY SPREADING LIGHT TO MODERATE SNOW SHOWERS ACROSS THE
REGION. THE SOUTHERN EXTENT OF THIS PRECIPITATION SHIELD WILL BE
FAIRLY LIMITED WITH MUCH OF THE SNOW CONFINED TO THE GREAT
LAKES...UPPER OHIO RIVER VALLEY...AND NORTHEASTERN STATES. THIS IS
A RESULT OF THE UPPER FLOW REMAINING MOSTLY ZONAL FARTHER TO THE
SOUTH LATER IN THE PERIOD.

AS A STRONG SURFACE ANTICYCLONE DOMINATES THE EASTERN PACIFIC...A
SERIES OF DISTURBANCES WILL SLIDE EASTWARD ABOVE THIS RIDGE
KEEPING CONDITIONS UNSETTLED OVER THE PACIFIC NORTHWEST AND UPPER
INTERMOUNTAIN WEST. ACCOMPANYING THESE SYSTEMS WILL BE A STEADY 25
TO 35 KNOT ONSHORE FLOW DRAWING AN ABUNDANCE OF PACIFIC MOISTURE
INLAND. THIS PLUME WILL EVENTUALLY INTERACT WITH THE OLYMPICS AND
CASCADES PRODUCING ENHANCED PRECIPITATION...MUCH OF THE TIME IN
THE FORM OF RAIN WITH AN OCCASIONAL MIX OF SNOW DURING THE
OVERNIGHT HOURS. SUCH CONDITIONS OVER THE REGION ARE EXPECTED TO
PERSIST THROUGHOUT MUCH OF THE WEEKEND GIVEN LITTLE CHANGE IN THE
WEATHER PATTERN.

A FRONTAL BOUNDARY SPRAWLED ACROSS THE UPPER INTERMOUNTAIN WEST
AND BACK TOWARD THE HIGH PLAINS WILL BE THE SITE FOR A DISTINCT
TEMPERATURE CONTRAST. THROUGHOUT THE NEXT COUPLE OF DAYS...A 30 TO
40 DEGREE GRADIENT WILL BE EVIDENT AS SUB-ZERO DEGREE TEMPERATURES
DOMINATE THE COLD SECTOR WHILE 30S AND 40S ARE MORE COMMONPLACE
TOWARD THE CENTRAL GREAT BASIN AND CENTRAL ROCKIES.

HPC QPF Discussion (Day 2-3):

...SRN/ERN TX TO LWR MS VLY...

A SRN STREAM SHRTWV WILL DIG THRU NRN MEXICO ON SAT... EMERGE OFF
THE TX COASTLINE ON SUN... BEFORE INTERACTING WITH A DIGGING
PAC/POLAR SHORT WAVE EMERGING FROM THE FRONT RANGE OF THE ROCKIES
OVER THE SRN PLAINS/LWR MS VLY. RETURN FLOW FROM THE GULF OF
MEXICO SHOULD CONCENTRATE ALONG A RELATIVELY ACTIVE INVERTED
SURFACE TROUGH OVER SRN/ERN TX ON SAT. THEN ON SUN... THIS
INVERTED TROUGH WILL BECOME MORE ACTIVE AND VIGOROUS AS THE
UPSTREAM BATCH OF UPPER DYNAMICS DIGS INTO TX FROM THE WEST AND
POSSIBLY INDUCES A SURFACE WAVE NEAR THE ARKLATEX. DECENT SPREAD
REVOLVES AROUND EACH SYSTEM AND THERE POSSIBLE INTERACTION... THUS
LARGE UNCERTAINTY WITH THE HEALTHY MOISTURE CONTENT. DUE TO THIS
UNCERTAINTY HPC USED A GENERAL BLEND OF THE ECMWF/GFS ON MASS
FIELDS AND QPF.

[wxman57]

The new Euro weeklies suggest the cold will stay around for another month. Early Spring Canceled. Sorry.

Party pooper! I'm hoping for at least some highs above 60 and a tad of sunshine for biking. I'm not going outside for an evening ride with temps in the 30s. I don't see any sign of a significant warm-up in the next few weeks, though.

[srainhoutx]

The new Euro weeklies suggest the cold will stay around for another month. Early Spring Canceled. Sorry.

Party pooper! I'm hoping for at least some highs above 60 and a tad of sunshine for biking. I'm not going outside for an evening ride with temps in the 30s. I don't see any sign of a significant warm-up in the next few weeks, though.

All that talk back in December for a warm and dry pattern had me longing for an early pool season. C'est la vie...

[srainhoutx]

Oh, I see. Now the 12Z GFS suggests cold air is coming down...lol...

[ticka1]

The new Euro weeklies suggest the cold will stay around for another month. Early Spring Canceled. Sorry.

Party pooper! I'm hoping for at least some highs above 60 and a tad of sunshine for biking. I'm not going outside for an evening ride with temps in the 30s. I don't see any sign of a significant warm-up in the next few weeks, though.

Not to rain on your parade wxman57! But it is winter and its nice to have some winter weather to enjoy around here! Actually getting to wear my winter coat and sweater's this year! Give us another 4-6 weeks of this and then we will all be praying for Spring and warmer temps!

[srainhoutx]

Now the Canadian (GEM) agrees with cold air returning on/near Thursday and also suggests a cutoff low at hour 144...

[wxman57]

12Z GFS is in agreement with the CMC/Euro in the passage of a cold front around next Thursday, dropping Houston temps back to the low to mid 30s.

[srainhoutx]

Yikes! The 12Z Euro now suggests the Arctic front will enter the Panhandle on Tuesday evening. And look out to our W. That model now suggests the cutoff low will move in a bit faster and cold air is becoming established across the Lone Star State...

[srainhoutx]

Ouch...looking wintry across parts of TX...

[harpman]

Uh oh, this place is going to fire up again!!! (at least until Wxman57 puts a stop to it! LOL!)

[srainhoutx]

The 12Z UKMET is onboard as well...

[tireman4]

I ....will....not....get.....caught....up....in.....this..time....nooooooooo!!!! Help......LOL.

[Mr. Weather]

any chance Houston could get anything form this one this time ? just curious

[TexasMetBlake]

I know...me either. I can already feel the forces working against me. NOOOOOOOOO...I feel myself becoming trapped at the computer already.