July 2014: Stalled Front/ Rain Chnaces To End July

[srainhoutx]

The trend via the 12Z suite of operational ensemble guidance suggests a polar front stalling somewhere near the Red River and heavy rainfall developing near the front. As is typical with this sort of situation, embedded short waves dropping SE as well as a potential for daily/nightly Mesoscale Convective Complexes poses an additional threat. As we always mention, such meso features cannot be accurately determined beyond a 6-12 hour time frame, if then. It does appear that after a rainless weekend/early next week, changes are indeed brewing in the Medium Range.

[tireman4]

Would it not be something if that front could come all the way to Houston? Boy, that would be something.

[ticka1]

Would it not be something if that front could come all the way to Houston? Boy, that would be something.

i am praying that it does happen!!!! Time for a cooler summer!!!!

[texoz]

Possible cool front is mentioned on Wunderground as part of the dynamics from the Japanese typhoon.

http://www.wunderground.com/blog/JeffMa ... rynum=2722

"his will amplify a trough low pressure over Alaska, causing a ripple effect in the jet stream over western North America, where a strong ridge of high pressure will develop, and over the Midwestern U.S., where a strong trough of low pressure will form. This jet stream pattern is similar to the nasty"Polar Vortex" pattern that set up during the winter of 2014 over North America, and will cause an unusually cool third week of July over the portions of the Midwest and Ohio Valley, with temperatures 10 - 20°F below average."

[srainhoutx]

A meandering upper low located across NE Mexico will slowly drift N along the Rio Grande Valley increasing storms chances to our W. Slightly higher PW's mainly along the Southern 2/3 of SE Texas should provide for a bit better rain chances the next couple of days. The Upper Ridge will take hold Sunday into early next week...then a big change is brewing.



A very potent Polar Vortex develops just N of the Great Lakes and drops an unusually strong July cold front S into the Southern Plains and into Texas. The fly in the ointment remains to be where the front pulls up stationary and the daily focus of heavy rains and storms. The Euro and Canadian models are rather bullish about our rain chances and actually drop the front to near the Coast by mid next week. The GFS is about 24 hours slower and not as wet, but does suggest the front hangs up close by across Central Texas next Thursday. After a few days of temperatures in the mid 90's and dry weather, it does appear that changes are ahead next week and the weather pattern could be rather active.

[unome]

I hope it makes it down here, will be keeping an eye on the front !

http://www.wpc.ncep.noaa.gov/medr/5dayf ... _conus.gif

[kayci]

JULY "COLD" front in Texas? Srain... You feeling okay????

[srainhoutx]

JULY "COLD" front in Texas? Srain... You feeling okay????

Strange year after everything we've experienced since 2008, isn't it kayci? I guess we have been conditioned to believe that the drought would never end as well as never ending days of 100F+ all summer long. Interesting fact...yesterday shortly before 5:00PM IAH finally hit 95F making 9th latest 95F recorded in Houston and tied with a very old record for the latest 95 dating back to 1919.

[kayci]

Strange is right! I take it the next thing to expect is snow this month?

[srainhoutx]

Interesting Extended Range Forecast Update from the Weather Prediction Center suggests near record cold anomalies are possible later next week across portion of our Region. Even the usually slower GFS is suggesting the frontal boundary will approach the Coast next Wednesday and also increasing rain chances as the front remains draped across the area.

EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1157 AM EDT THU JUL 10 2014

VALID 12Z SUN JUL 13 2014 - 12Z THU JUL 17 2014

...HEAT TO CONTINUE IN THE PAC NW...

...RECORD COLD POSSIBLE IN THE CENTRAL/SOUTHERN PLAINS AND GREAT
LAKES REGION...


...OVERVIEW AND GUIDANCE PREFERENCES...

A HIGHLY ANOMALOUS AMPLIFICATION OF THE FLOW ACROSS NORTH AMERICA
IS INDICATED BY THE GLOBAL NUMERICAL MODELS AT THE MEDIUM RANGE. A
DEEP UPPER LOW... NOT THE POLAR VORTEX AS ITS ORIGINS ARE FROM THE
NE PACIFIC... WILL SWING THROUGH THE GREAT LAKES EARLY NEXT WEEK
WITH AN IMPRESSIVE COLD SHOT OF AIR INTO THE CENTRAL AND THEN
SOUTHERN PLAINS AND THE MIDWEST. THE EUROPEAN CENTRE ENSEMBLE MEAN
HAS BEEN THE STEADIEST OF THE MEANS FROM THE VARIOUS MODELING
CENTERS OVER THE PAST FEW DAYS OF DATA CYCLES... AND THE
DETERMINISTIC MODELS HAVE MOSTLY CONVERGED TOWARDS ITS IDEA. THE
ECMWF... THOUGH IT HAS BEEN ON THE EXTREME SIDE OF THE ENTIRE
ENSEMBLE SPREAD... HAS BEEN INSISTENT ON ADVERTISING QUITE THE
TEMPERATURE EXTREMES -- BOTH HOT AND COLD -- FOR THE CONUS NEXT
WEEK. THE GFS HAS BEEN GENERALLY WITHIN THE ENSEMBLE SPREAD OVER
THE LAST 48 HRS BUT LAGS BEHIND THE GREATER CLUSTER OF THE
ECMWF/CMC/UKMET WITH THE FRONTAL PROGRESSION THROUGH THE SOUTHERN
PLAINS EARLY NEXT WEEK. RELIED ON A CONSENSUS BLEND EARLY IN THE
PERIOD BEFORE TRENDING TO A ECMWF/ECENS/GEFS BLEND FOR THE BALANCE
OF THE FORECAST... WHICH MAINTAINS CONTINUITY WELL.


...SENSIBLE WEATHER HIGHLIGHTS...

THE IMPRESSIVE FULL-LATITUDE RIDGE OVER THE WEST IS EXPECTED TO
SEND TEMPERATURES SOARING OVER EASTERN WASHINGTON AND THE ADJACENT
LOWLANDS OF OREGON AND IDAHO. AFTERNOON HIGHS MAY WELL RANGE
BETWEEN 100F AND 110F FOR MUCH OF THE PERIOD... CLOSE TO RECORD
HIGHS FOR BOTH MAX AND MIN. PRECIP SHOULD BE SCARCE OR
NON-EXISTENT WEST OF THE DIVIDE IN THE NORTHERN ROCKIES. FOR THE
CENTRAL/EASTERN/SOUTHERN CONUS... THE UPPER LOW WILL CARRY A LEAD
SFC BOUNDARY EASTWARD AND SOUTHWARD WITH A REINFORCING COLD PUSH
BEHIND IT. TEMPERATURE ANOMALIES ALOFT DROP INTO THE -2 TO -3
STANDARD DEVIATIONS RANGE PER THE ENSEMBLE MEANS. SPC HAS
HIGHLIGHTED A SEVERE THREAT IN THE NORTHEAST/I-95 CORRIDOR ON
TUE/D5 IN ADVANCE OF THE FRONT. INDEED CONVECTION IS POSSIBLE IF
NOT LIKELY ALONG ITS PATH... WHICH WILL MODULATE THE SPEED OF THE
FRONTAL PROGRESSION INTO THE SOUTH. DESPITE BEING NEAR THE CLIMO
MAX TIME OF THE YEAR FOR TEMPERATURES... THE MODELS INDICATE THAT
THE SFC BOUNDARY WILL HEAD TOWARD THE GULF COAST BY LATE NEXT
WEEK... THOUGH IN A WEAKENED STATE. THE BELOW AVERAGE TEMPERATURES
SHOULD SPREAD SOUTHWARD BEHIND THE FRONT INTO TX/OK WHERE RECORD
LOW MINS/MAXES ARE POSSIBLE AS 850 TEMPS DROP TO NEAR MONTHLY
RECORD LOWS.


FRACASSO/CISCO

[tireman4]

Yeah, this is a really potent front for folks up north. The Marquette, Michigan NWS AFD alluded to it:

WHEN COMBINED WITH THE COLD AIRMASS OVERHEAD...HIGH TEMPS
MAY STRUGGLE TO GET ABOVE 50 IN SOME SPOTS ON TUE...WHICH WOULD BE
RECORD BREAKING FROM A MINIMUM HIGH TEMPERATURE PERSPECTIVE.


http://forecast.weather.gov/product.php ... glossary=1

Stay tuned folks. This could be interesting.

[Rip76]

Wow - I was watching all of that moisture streaming up from South Texas today. As soon as it got about 75-100 miles south of Galveston, "poof" gone.

Grrr.

[jasons2k]

An outflow boundary from the earlier storms is draped across the northern & eastern Harris County line, and then east over the Chambers/Liberty county lines. It is almost stationary but slowly sagging south. I wonder if more storms will fire along it later today.

[djjordan]

In all the years of being on this forum, I've never heard a discussion of a cold front in July. For my friends up in Michigan, would appear that this year is a short summer for ya. I for one have been enjoying this summer much more than in years past.

[jasons2k]

Since it's July, the peak of the summer season, the question is if this is the first front of the fall season, or the last front of the spring season. Since all spring we seemed to run a month behind on temps and had many late-season cold snaps, my books will call this a continuation of the never-ending 2014 spring/winter season.

[Andrew]

The most promising aspect of next weeks cold front is the orientation of the upper level trough. The Euro has been the most bullish with rain chances across SE Texas (and most of Texas for that part), due to the amplified ridging that progresses south from the Canadian border. A 1026mb surface high would force the front farther south than what the GFS is showing. This is also the reason why the GFS is slower than the Euro. Either way though, with mid level ridging retreating west to the four corners region this positively tilted trough could stall across much of Texas, from the panhandle region to SE Texas. Finally, both the GFS and Euro suggest that multiple shortwaves could rotate around the base of the trough, leeward of the Rockies. While the GFS has been struggling with Convective Feedback issues, this could enhance rain chances even more, allowing multiple rounds of rain. The key will be where the frontal boundary stalls out.

[Rip76]

Good stuff Andrew, thanks.

[Ptarmigan]

A cold front in July. Very unusual. If the cold front made it to the Gulf of Mexico, something tropical could brew.

[Ptarmigan]

The most promising aspect of next weeks cold front is the orientation of the upper level trough. The Euro has been the most bullish with rain chances across SE Texas (and most of Texas for that part), due to the amplified ridging that progresses south from the Canadian border. A 1026mb surface high would force the front farther south than what the GFS is showing. This is also the reason why the GFS is slower than the Euro. Either way though, with mid level ridging retreating west to the four corners region this positively tilted trough could stall across much of Texas, from the panhandle region to SE Texas. Finally, both the GFS and Euro suggest that multiple shortwaves could rotate around the base of the trough, leeward of the Rockies. While the GFS has been struggling with Convective Feedback issues, this could enhance rain chances even more, allowing multiple rounds of rain. The key will be where the frontal boundary stalls out.

August 2004 had a strong cold front come to Houston. Houston saw lows of low 60s that time.

[jasons2k]

I remember back in 1986, living in Savannah, GA, we had a high temperature of 58 one day in August. It was eerie -- a chilly & foggy day with a steady temperature. I remember riding my bike in jeans and a jacket in summer.