January: Seasonal Temps To End The Month

[srainhoutx]

Fog continues to plague much of our region (Texas/Oklahoma/Louisiana) as temps and dew points continue to rise daily. A very slow moving weak frontal boundary is draped across the Red River Valley and will slowly drop a bit further S before stalling and washing out over the weekend.

Attention then turns to our W. A Gulf of Alaska storm will begin to move inland along the Pacific NW and drop S into Southern California during the late weekend time frame. Very rich Pacific tropical moisture will stream inland across the W and into the Great Basin/Desert SW setting the stage for a very wet and stormy pattern in California, Arizona and New Mexico. As the storm system drops into Southern California, cold air from NW Canada will drop S into the Great Basin where temps will fall to the 10-20 degree below normal range. Valley rains and higher elevation wet snow will develop this weekend to our W.

Across Texas, Oklahoma and Louisiana, deep Gulf moisture will surge inland as pressures fall to our W setting the stage for a warm, breezy and humid Monday into Tuesday of next week. There are differences that are still being seen via the guidance as they flip flop and switch scenario solutions. The 00Z Euro and its ensembles swapped place with the GFS/GEFS suggesting a more progressive positive tilted trough sweeping across Texas on Tuesday/Wednesday, while the GFS/GEFS is now slower. The GGEM is even slower to eject the energy off of Baja along the NW Coast of Mexico and is suggesting a 500mb low will linger most of next week. PW's rise to nearly 2 standard deviations above normal for this time of year for the NW Gulf Coast which raises an eyebrow for a heavy rainfall potential if capping can be overcome due to a SW flow aloft ahead of the approaching storm/trough to the W.

The SPC has outlined a Day 6 issuance that includes NE TX/SE OK/N LA/AR/SE MO/S IL/W KY/E TN. As the SPC discussion explains, this outline area may need to be reconfigured during the next several days due to the lack of continuity via the Global operational and ensemble guidance.

In the cold sector, snow levels are expected to drop to the desert valley floor early next week into the mid week time frame as much colder air filters S. Wintry weather will also be an issue N of the Arctic boundary as cyclogenesis begins Monday/Tuesday across the Southern Plains as the 500mb trough axis begins to eject E and very cold air builds across the Northern Plains/Great Lakes Region. Very heavy rainfall is possible along the Northern Gulf Regions into the SE as training storms are possible. This remains a very complex and complicated forecast, so expect changes as we head into the weekend and early next week.


HPC QPF/Day 7:

The attachment 01242013 HPC QPF Day 7 p168i.gif is no longer available

SPC/Day6:

The attachment 01242013 SPC Day 6 day48prob.gif is no longer available

00Z Euro Ensembles:

06Z GEFS:

00Z GGEM:

[Texas Pirate]

Here is a snippet from disco HGX today
Hopefully warm pattern but not much rain

IF ONE IS TO USE THESE PAST FEW DAYS OF MODEL SOLUTIONS TO GAUGE
THIS WINTER SEASON`S TRENDS...THEN WINTER`S DAYS MAY BE DWINDLING
MORE RAPIDLY THAN EVEN WE ARE USED TO HERE IN SOUTHEASTERN TEXAS.
EACH SUCCESSIVE RUN HAS LESS OF A DIFFERENTIATION BETWEEN AIR MASS
CHARACTERISTICS SO...AS A CONSEQUENCE...EACH INCOMING FRONTAL
BOUNDARY PACKS LESS OF A PUNCH AS DID THE RUN BEFORE IT. THE MOST
RECENT CLIMATIC OUTLOOKS HAVE TEXAS FALLING INTO AN ABOVE NORMAL
TEMPERATURE /BELOW NORMAL PRECIPITATION PATTERN THROUGH APRIL.

[srainhoutx]

The 12Z Operational GFS is trending toward a more neutral trough axis that tends to favor an increase in a severe weather episode potential should that scenario verify.

126 Hour:

The attachment 01242013 12Z GFS f126.gif is no longer available

132 Hour:

138 Hour:

144 Hour:

[srainhoutx]

HPC Extended Range Morning Update:


EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER COLLEGE PARK MD
1057 AM EST THU JAN 24 2013

VALID 12Z SUN JAN 27 2013 - 12Z THU JAN 31 2013

MEDIUM RANGE MODELS AND INDIVIDUAL ENSEMBLE MEMBERS CONTINUE TO
SHOW A MODERATE AMOUNT OF SPREAD AND IN SOME CASES MEANINGFUL RUN
TO RUN CHANGES WITHIN A MORE AGREEABLE MEAN FCST OF A WEST COAST
TROF BECOMING STEADILY BROADER AS ITS AXIS TRAVELS TOWARD THE
CNTRL OR E-CNTRL CONUS. WHILE THERE ARE CURRENTLY SOME DETAILS IN
THE LATEST OPERATIONAL SOLNS THAT COULD MERIT PARTIAL WEIGHTING IN
A DETERMINISTIC FCST THROUGH AT LEAST DAY 5 TUE... RELATIVELY POOR
MODEL CONTINUITY THUS FAR RECOMMENDS HOLDING ONTO A MORE
CONSISTENT 00Z GEFS/ECMWF ENSEMBLE MEAN BLEND FOR THE DAYS 3-7
FCST UNTIL THE MODELS STABILIZE. THE ONE SIGNIFICANT ADJUSTMENT
IN THIS SOLN REFLECTS GUIDANCE AS A WHOLE TRENDING FASTER WITH THE
FRONT DROPPING FROM WRN CANADA INTO THE NRN TIER CONUS EARLY NEXT
WEEK.

GUIDANCE BEGINS TO DIVERGE DURING THE FIRST HALF OF THE PERIOD
ACROSS THE WEST AS THE 00Z ECMWF/CANADIAN TREND FASTER WITH THE
TROF DUE TO FLOW STREAMING SEWD ALONG OR INLAND FROM THE BC COAST
HAVING A MORE EWD COMPONENT THAN IN THE 00Z/06Z GFS OR 00Z UKMET.
IN ADDITION THE 00Z ECMWF HAS THE MOST AMPLIFIED DEPICTION OF
ENERGY ROUNDING THE UPSTREAM EPAC RIDGE BY LATE MON INTO TUE.
OVER RECENT DAYS THERE HAS BEEN A HINT OF SOME SWWD ELONGATION OF
THE OVERALL TROF EVEN TO THE POINT OF FORMING A CLOSED LOW EVEN IF
ONLY BRIEFLY. WHAT OPERATIONAL SOLNS HAD SHOWN THIS IDEA
PREVIOUSLY HAVE TRENDED AWAY. SOME 00Z ENSEMBLE MEMBERS STILL
SHOW THIS SCENARIO THOUGH... WITH CMC MEMBERS SHOWING THE HIGHEST
PERCENTAGE AND ECMWF MEMBERS THE LOWEST. TELECONNECTIONS RELATIVE
TO THE EPAC RIDGE HAVE SUPPORTED SOME SWWD ELONGATION OF THE MEAN
TROF BUT LATEST D+8 MEANS INDICATE THAT THE RIDGE MAY NOT REMAIN
SUFFICIENTLY STRONG TO SUPPORT TOO MUCH SWWD ELONGATION OF THE WRN
TROF. LESS ELONGATION IN THE 06Z GEFS MEAN VERSUS THE 00Z RUN
ADDS MODEST SUPPORT TO LEAN AWAY FROM THE SLOWER/AMPLIFIED SIDE OF
THE SPREAD.

DIFFS IN THE HANDLING OF LEADING WRN CONUS ENERGY AND UPSTREAM WRN
CANADA FLOW RESULT IN SIGNIFICANT DETAIL/TIMING DIFFS FOR CNTRL
PLAINS TO UPR GRTLKS SFC LOW PRESSURE AROUND LATE MON THROUGH LATE
TUE... BUT THE VARIED SOLNS DEVELOP SURPRISINGLY GOOD CLUSTERING
BY EARLY DAY 6 WED. ASIDE FROM THE 00Z CMC THE MAIN THEME IN
OPERATIONAL SOLNS IS FOR A STRONGER/SLOWER PLAINS SFC LOW THAN
SEEN IN THE LATEST ENSEMBLE MEANS. IT WOULD NOT BE SURPRISING TO
SEE AN EVOLUTION SOMEWHERE BETWEEN THE OPERATIONAL AVG AND
ENSEMBLE MEANS BUT RECENT GFS/ECMWF/CMC RUNS HAVE NOT STABILIZED
ENOUGH YET TO STRAY FROM THE ENSEMBLE MEANS WITH MUCH CONFIDENCE.

BY DAYS 6-7 WED-THU THE DIFFS ALOFT AFFECT TIMING OF THE COLD
FRONT CROSSING THE ERN STATES AND EXISTENCE OF A FRONTAL WAVE.
THE 00Z/06Z GFS THAT WERE SLOWER/MORE AMPLIFIED ALOFT OVER THE
WEST ARE SLOWEST WITH THE COLD FRONT AND SHOW A FAIRLY STG WAVE
LIFTING NEWD TOWARD THE NERN COAST. THE 00Z ECMWF/CMC ARE ABOUT A
DAY FASTER WITH THE FRONT AND SHOW MINIMAL WAVINESS ALONG IT.
GIVEN THIS SPREAD AND PRIOR CONTINUITY... THE ENSEMBLE MEANS THAT
ARE BETWEEN THESE TWO EXTREMES PROVIDE THE MOST APPEALING SOLN AT
THIS TIME.



EXPECT BELOW NORMAL TEMPS OVER MOST OF THE WEST ESPECIALLY AFTER
SUN... WITH THE SRN HALF TO 2/3 OF THE REGION LIKELY TO TREND
DRIER BY THE LATTER HALF OF THE PERIOD. RAIN/SNOW OVER THE WEST
IS NOT FCST TO BE EXCEPTIONALLY INTENSE IN GENERAL BUT SOME
LOCATIONS IN FAVORED TERRAIN MAY STILL SEE DECENT MULTI-DAY
TOTALS. CNTRL-ERN AREAS WILL SEE A PRONOUNCED WARMING TREND AHEAD
OF THE INITIAL WRN SYSTEM BUT COOLER AIR WILL SPREAD EWD WITH
TIME. AREAS FROM THE N-CNTRL PLAINS INTO THE UPR GRTLKS MAY
EXPERIENCE A PERIOD OF WIND-DRIVEN SNOW IN THE FIRST HALF OF NEXT
WEEK DEPENDING ON CNTRL PLAINS TO UPR GRTLKS SFC EVOLUTION.
BEHIND THIS SYSTEM THE CORE OF COLDEST AIR SHOULD BE OVER THE NRN
PLAINS/UPR MS VLY BY TUE-WED. GULF INFLOW AHEAD OF THE TRAILING
COLD FRONT TRACKING TOWARD/THRU THE EAST SHOULD ENHANCE RNFL OVER
SOME AREAS FROM THE MS VLY EWD BY TUE-WED. THERE IS CONSIDERABLE
UNCERTAINTY ON AMTS DUE TO DIFFS IN FRONTAL TIMING/WAVINESS...
WITH AN ENSEMBLE MEAN PREFERENCE BETWEEN THE FASTER/LIGHTER ECMWF
AND SLOWER/HVY GFS EXTREMES.

RAUSCH

[C2G]

Pirate, I'm liking what I'm reading. You and wxman57 keep up the good work and we'll kick winter out of here soon enough.

[jasons2k]

I like the idea of winter ending early, but the pattern does concern me. It seems like for several years running now, the switch flips in early February and we get stuck in this very warm zonal/SW flow pattern with capping aloft. It's just not a good way to start the spring storm season (or lack thereof) if we want to hammer away at this long-term dry pattern.

I'm starting to wonder if this is a 'new normal' for us, meaning the desertification of the SW US is spreading (as modeled on the global warming climate models) or if this is just some sort of decadal or multi-decadal oscillation related to global climate patterns & ocean currents.

[cristina99]

That makes me sad. I guess I am the minority when it comes to Texas weather. I do not like the hot dry summery months and we don't have spring anymore - it leaps right into the warmer and hot temps. It's good to have lots of cold - that way we have the beautiful flowers like we should in the spring months not Bluebonnets in February. Oh well, there's always next year!

[jasons2k]

Oh come on gang - it's not that bad. 70's and 80's isn't summer - that's spring. And pleasant for probably 95% of us. Now if it gets into April and we're hitting the 90's, then complain about it being "summer" already. This is Houston, after all.

[srainhoutx]

Well the 12Z Euro certainly would throw a monkey wrench regarding the storm system next week. That model has flipped to a closed core upper low off the Southern California Coast and stalls that feature. The models are likely not handling the upper air pattern well at all...LOL

[Texas Pirate]

Okay it looks like I'm in the semi- minority here
Whats wrong with hot wx, flip flops, sweet tea (or beer)
and sailing on the bay???? Heaven. Pure heaven.

Although deep in my heart I do NOT want that drought summer back
(even though I do feel we are trending so.....)
I am a fan of "funderstorms" ~love that wx word.
But anything under 90 makes me shiver.

Yes, I'm crazy

[jasons2k]

Cheers to that. Houston isn't that bad. 90's, puffy clouds, periodic thunderstorms, and humidity 95% of the summer...I can deal with that. Now Wichita Falls....yeah...now that place is truly hot!

[wxman57]

Our summer afternoon relative humidity is close to 50%, not 95% (Temp 92 / dew point 72). On hotter days, the RH is even lower. To get to a 95% RH on a summer afternoon would take a temperature of, say 95F and a dew point of 93F - something that's never happened in Houston. Of course, almost every day summer or winter the RH is between 95% and 100% at sunrise when the temperature and dew point are close together. This morning's relative humidity was 100%, same as it was during the cold days earlier this month.

[jasons2k]

Yes, I know. I didn't mean (or say) 95% relative humidity -- I said "90's, puffy clouds, periodic thunderstorms, and humidity 95% of the summer"

...Meaning about only 5% of the time it's a miserable 100plus & dry...like a place like Wichita Falls...

[C2G]

Been in this area since 72. In my childhood I recall a few snow events in 72 or 73, 81, extended freezing temps in 83, extreme cold in 89, snow that didn't stick in 93 or 94, snow in 04 and 08, 09.
But, this is a sub-tropical climate after all, so warm to hot temps is something that happens every year. Close to a 100% chance it will happen.
Cold without snow or sleet is just miserable to me. Have to bundle up before going anywhere. Can't wear shorts, T-shirts, or sandals. Can't bask in the sun or have nice invigorating walks in the park.
I have thin blood acclimated to this sub-tropical climate and if I wanted a guarantee of extreme cold/snow every winter I'd probably move maybe six hundred to a thousand miles north of this area.

[Ptarmigan]

Our summer afternoon relative humidity is close to 50%, not 95% (Temp 92 / dew point 72). On hotter days, the RH is even lower. To get to a 95% RH on a summer afternoon would take a temperature of, say 95F and a dew point of 93F - something that's never happened in Houston. Of course, almost every day summer or winter the RH is between 95% and 100% at sunrise when the temperature and dew point are close together. This morning's relative humidity was 100%, same as it was during the cold days earlier this month.

Houston has come close to 90°F dew points. The highest dew point in Houston is 86°F on June 7, 1979.
http://forums.khou.com/viewtopic.php?f=2&t=1613

If one really want high dew points, go to the Persian Gulf and Red Sea region. The highest is 95°F in Dhahran, Saudi Arabia. The temperature was 108°F with a heat index of 174°F! Now that makes Houston feel like the Arctic!

Ask Tom why: What is the highest dew point ever recorded?
http://articles.chicagotribune.com/2011 ... -corn-crop

[Ptarmigan]

Been in this area since 72. In my childhood I recall a few snow events in 72 or 73, 81, extended freezing temps in 83, extreme cold in 89, snow that didn't stick in 93 or 94, snow in 04 and 08, 09.
But, this is a sub-tropical climate after all, so warm to hot temps is something that happens every year. Close to a 100% chance it will happen.
Cold without snow or sleet is just miserable to me. Have to bundle up before going anywhere. Can't wear shorts, T-shirts, or sandals. Can't bask in the sun or have nice invigorating walks in the park.
I have thin blood acclimated to this sub-tropical climate and if I wanted a guarantee of extreme cold/snow every winter I'd probably move maybe six hundred to a thousand miles north of this area.

It did not snow in 1972, but snowed three times in 1973 as it was a strong El Nino that time.

Houston Snow History
http://www.wxresearch.com/snowhou.htm

Winter weather is harder to predict than heat waves in Houston and America. Heat waves tend to be one or if not the worst and deadliest weather event.

[srainhoutx]

EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER COLLEGE PARK MD
1210 AM EST FRI JAN 25 2013

VALID 12Z MON JAN 28 2013 - 12Z FRI FEB 01 2013


WILL NOT BELABOR THE BOTTOM LINE FOR THE CONFIDENCE IN THIS MEDIUM
RANGE FORECAST: IT IS VERY LOW. THE BIG UNCERTAINTY IS HOW MUCH OF
THE ENERGY DROPPING ALONG THE WEST COAST TUCKS OFFSHORE EARLY IN
THE PERIOD--A SITUATION THAT WOULD LEAD TO A MUCH SLOWER EJECTION
OF THE TROUGH. THE 12Z/24 EUROPEAN CENTRE GUIDANCE KEPT THE TROUGH
OUT OF PLAY BY UNDERCUTTING THE RIDGE TO THE NORTH. THE REMAINDER
OF THE MODELS, INCLUDING PREVIOUS RUNS OF THE ECENS MEAN, KEPT THE
ENERGY CLOSE ENOUGH TO THE MAIN BAND OF WESTERLIES TO ALLOW IT TO
KICK INTO THE SOUTHERN PLAINS AND PHASE WITH THE NEXT SLUG OF
ENERGY DROPPING DOWN FROM CANADA. THE EUROPEAN GUIDANCE IS OFTEN
THE FIRST TO LATCH CORRECTLY ONTO A NEW TREND, SO GAVE IT HALF THE
WEIGHTING IN THE MANUAL BLEND. BALANCED THE REMAINDER OF THE BLEND
WITH THE MORE PHASED/PROGRESSIVE 12Z/24 GEFS MEAN. THE RESULT IS
THE AMORPHOUS BLEND OF TWO DISPARATE ENSEMBLE MEANS, WHICH RENDERS
DISCUSSION OF THE PARTICULARS OF ANY GIVEN SYNOPTIC SYSTEM MOOT
UNTIL THE BIG PICTURE BECOMES CLEARER.

THE SAFEST THING TO NOTE ABOUT THE SENSIBLE WEATHER IS THE MASSIVE
WARM-UP FOR THE NATION EAST OF THE ROCKIES, WITH THE ANOMALIES
FLIPPING FROM DOUBLE-DIGIT NEGATIVE TO DOUBLE-DIGIT POSITIVE
ACROSS THE UPPER MIDWEST DAYS 3 AND 4.


CISCO

[wxman57]

"Massive warm-up" ... music to my ears. Had a nice 20-mile bike ride yesterday after work. Shorts and a short-sleeved shirt for the first time in 2013. Was only slightly cool on the way home at 6pm.

Euro & GFS remain in opposite camps as far as next week's weather. Euro has the slower, stronger trof/upper low arriving much later than the faster/weaker GFS. GFS is starting to trend toward the Euro, though. Perhaps the warm temps will continue until later next week?

[Portastorm]

I think you're right wxman57. I'm watching the 12z GFS roll in and it definitely is trending towards the Euro solution for a more pronounced, robust cut-off low which is slower moving.

[wxman57]

The 12Z GFS is sort of trending toward a deeper trof but it still brings the front through Houston early next Wednesday morning vs. late Thursday or Friday for the 00Z Euro.