July 2014: Stalled Front/ Rain Chnaces To End July

[tireman4]

If we ( Houston) could just get one day of that weather. Just one day. Heaven.

[srainhoutx]

The interesting thing with this expected pattern is just how strong the 500mb low that is rapidly dropping S over the Western Great Lakes Region is going to be and how deep of a trough it is going to carve out. We certainly do not see this sort of deep 500mb low in mid July which 3+ standard deviations below normal and should allow for multiple short waves to drop SE from Western Canada and round the base of the deep trough. Last week we only expected that strong upper low to be positioned N of the Great Lakes and now it appears it may drop as far S as the Ohio River Valley.

[tireman4]

And the Marquette, Michigan NWS was right. This is cold for them right now. Goodness gracious. Here is the AFD

TUE...THE SHRA...ENHANCED BY UPSLOPE INTO THE TERRAIN OF N CNTRL
UPPER MI...WILL CONTINUE INTO AT LEAST EARLY TUE AFTERNOON BEFORE
THE DEEPER MOISTURE MOVES OFF TO THE EAST. TEMPS WILL BE WELL BELOW
SEASONAL AVERAGES (NEAR THE LOWER END OF GUIDANCE) WITH HIGHS IN THE
MID 50S N DOWNWIND OF NNW FLOW OFF OF LAKE SUPERIOR AND IN THE LOWER
60S SOUTH.

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

Wow. Just wow. I post this because this is a stout air mass for this time of year.

It is 54F up there right now.

[Portastorm]

I'm liking how NWSFO EWX is bullish on rain chances this week for south central Texas!

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
313 PM CDT MON JUL 14 2014

.SHORT TERM (TONIGHT THROUGH TUESDAY NIGHT)...
A WEAK TUTT LOW/AXIS ACROSS THE MID/UPPER COAST HAS ALLOWED
SCATTERED SHOWERS AND THUNDERSTORMS TO DEVELOP ACROSS SERN TEXAS.
MOST OF THIS ACTIVITY WILL STAY TO OUR EAST...BUT AN ISOLATED
STORM COULD REACH THE FAR EASTERN TIER OF OUR CWA BEFORE SUNSET.
TO OUR NORTH...CONVECTION HAS BEGUN TO INCREASE ALONG THE RED
RIVER/N TX AHEAD OF A WEAK FRONT. THESE STORMS WILL MOVE INTO
CENTRAL TEXAS OVERNIGHT AND COULD SEE A FEW STORMS ENTER OUR NRN
ZONES BEFORE SUNRISE. THE FRONT WILL CONTINUE TO PUSH SOUTHWARD ON
TUESDAY. WHILE THE FRONTAL PASSAGE WILL NOT BRING ANY APPRECIABLE
CHANGE IN TEMPERATURES...THE FRONTAL BOUNDARY WILL PROVIDE FOCUS
FOR STORM DEVELOPMENT. CONVECTION WILL BECOME MORE WIDESPREAD
DURING THE AFTERNOON HOURS AS STORMS DEVELOP ALONG OUTFLOW
BOUNDARIES...AND THE FRONT DIPS SOUTHWARD INTO THE CWA DURING PEAK
HEATING. MODEL SOUNDINGS INDICATE AN INVERTED-V SET UP...WHICH
TRANSLATES TO THE POTENTIAL FOR STRONG MICROBURST/DOWNBURST WINDS
WITH THE THUNDERSTORMS. PW VALUES ACROSS THE AREA WILL INCREASE TO
1.9-2 INCHES...SUGGESTING ISOLATED HEAVY DOWNPOURS ARE ALSO POSSIBLE.
CHANCES FOR RAIN WILL CONTINUE INTO TUESDAY NIGHT AS THE FRONT
LINGERS ACROSS THE AREA.

&&

.LONG TERM (WEDNESDAY THROUGH MONDAY)...
AN UNSTABLE PATTERN WILL REMAIN ALOFT ON WEDNESDAY AS THE FRONT
ATTEMPTS TO RETREAT NORTHWARD...KEEPING A SLIGHT CHANCE FOR STORMS
ACROSS EASTERN PORTIONS OF THE REGION. MODELS CONTINUE TO INDICATE
SHORT-WAVE TROUGHING WILL ALLOW A COUPLE OF MESOSCALE CONVECTIVE
SYSTEMS TO DEVELOP ACROSS THE CENTRAL/SRN PLAINS DURING THE LATTER
HALF OF THE WORK WEEK. THE GFS CONTINUES TO BE THE DRY OUTLIER AND
HAVE OPTED TO CONTINUE WITH A BLEND OF PREVIOUS FORECAST/ECMWF
HIGHLIGHTING THE BEST COVERAGE OF STORMS TO BE THURSDAY NIGHT INTO
FRIDAY MORNING. PW VALUES WILL AGAIN BE ABOVE AVERAGE AT 1.8-2+
INCHES...SO LOCALLY HEAVY DOWNPOURS ARE AGAIN EXPECTED. THERE IS
THE POTENTIAL FOR MINOR FLOODING...MAINLY ACROSS LOW-LYING AND
FLOOD PRONE AREAS (SUCH AS INTERSECTIONS/LOW WATER CROSSINGS)

[unome]

I hear thunder, fingers crossed it will reach us this time :)

http://weather.cod.edu/satrad/nexrad/in ... X-N0Q-1-48

[jasons2k]

Lots of thunder here. The storm is just to my west, the edge about a mile away. I could use the rain as I only had a trace yesterday, and my lawn is quickly drying out.

[srainhoutx]

I dumped .97 from the gauge this morning from the storms that developed late yesterday afternoon across NW Harris County. Today brought an additional .17 so my yard is happy.

[BlueJay]

High and dry here.

[srainhoutx]

Storms are developing across much of the front range into Texas and ahead of the pre frontal trough that is currently stretched out from the Panhandle extending SE to just S of the Metroplex and on E. Some of the shorter term meso computer models suggest that these storms will continue to drop S as the night progresses.

[ticka1]

i am wishcasting for the front to inch its way down to the coast!!!!

[Andrew]

The 12z European showed a couple of waves making its way all the way to the coast of SE Texas. The gfs was a little less bullish with this approach and suggested that the front would initially stall across central Texas to then get pushed across the state/closer to the coast with the shortwave that should cross the state on Wednesday/Thursday. Interesting to note that a lot of the models suggest some sort of mcs forming in North Texas or South Oklahoma. General movement will be to the SE and I wouldn't be surprised to see leftover boundaries being a focal point for additional storms, especially in the central parts of the state. The weekend currently shows the best possibility for showers and storms as the front gets closer to the coast.

[Ptarmigan]

The 12z European showed a couple of waves making its way all the way to the coast of SE Texas. The gfs was a little less bullish with this approach and suggested that the front would initially stall across central Texas to then get pushed across the state/closer to the coast with the shortwave that should cross the state on Wednesday/Thursday. Interesting to note that a lot of the models suggest some sort of mcs forming in North Texas or South Oklahoma. General movement will be to the SE and I wouldn't be surprised to see leftover boundaries being a focal point for additional storms, especially in the central parts of the state. The weekend currently shows the best possibility for showers and storms as the front gets closer to the coast.

Interesting the weekend could be the wettest. I wonder if it would late Friday night to early Saturday morning.

[Andrew]

BTW the HRRR, RAP, and GFS all suggest that the current convection across central Texas could intensify overnight affecting those in SE Texas tomorrow morning.

[srainhoutx]

The pure frontal trough extends from Central and the Northern Counties of SE Texas on E into Central Louisiana. The actual cold front is further N across Oklahoma this morning. The showers/storms along the pre frontal trough should weaken and leave outflow boundaries draped across Central and SE Texas allowing for sea breeze storms to fire with daytime heating and boundary collisions later this afternoon. The upper ridge is being forced W as the Central/Eastern trough associated with a stout 5H (upper low) spinning near the Great Lakes pulls down additional cool/dry air from Canada into the Plains. Storms should fire again this afternoon along the front range of the Rockies and drop SE in the NW flow aloft.

A potent short wave is still expected to arrive on Thursday from Western Canada and cross the Southern Plains and possibly bring a more wide spread threat for heavy rainfall as a convective complex (MCS) develops across N Central Texas.

[srainhoutx]

Morning Update from Jeff:

Ongoing activity this morning across our northern counties ahead of a pre-frontal trough over N TX.

Fairly active few days for the region as a frontal boundary sags southward and stalls and several upper level disturbances move across the state in the NW flow aloft. Periods of thunderstorms will be likely each day especially late Thursday into Friday.

Radar shows a band/cluster of thunderstorms from western Louisiana to east of College Station slowly moving southward this morning. Storms appear to be weakening slightly and this trend should continue this morning. Moisture has increased over the region with PWS running 1.8-2.0 inches and this is plenty of moisture to get things going with heating today. Trigger temperatures in the upper 80’s and lower 90’s combined with the inland moving seabreeze and southward moving outflow boundaries from the current activity will set the stage for a fairly active afternoon. Main threats will be frequent lightning and very heavy rainfall.

Frontal boundary stalls across central TX into SW LA on Wednesday with additional storms likely to develop during the afternoon hours as the air mass remains unstable and moist. Think the best concentration will be from College Station to Houston to High Island or closest to the stalling frontal zone. Once again heavy rainfall will be the main threat.

Thursday-Friday:

A powerful short wave over the NW US will drive SE and arrive into TX late Thursday. In almost a spring like pattern a low level jet develops and surges sustained moisture into the region while strong lift overspreads the region from NW to SE late Thursday night into Friday. Model solutions a pointing toward a large MCS developing over NW TX late Thursday afternoon and spreading across much of central and SE TX overnight into Friday. Moisture values surge to 2.0-2.2 in of PW suggesting an excessive rainfall threat with any slow moving or training storms. Severe threat will also be enhanced with any local bowing line segments producing wind damage.

Overall pattern for the next several days will be highly meso scale driven with each thunderstorm cell producing new nearby cells on its outflow boundaries…much like the last few days. Best rain chances will be dependent on where boundaries collide or set up and this is impossible to determine much more than a few hours in advance, but will have a significant impact on convective coverage each day. Synoptic scale lift Thursday night into Friday supports more widespread coverage and less dependence on meso boundaries.

Best rainfall amounts through the period will be NE of a line from College Station to High Island with lesser amounts around Matagorda Bay.
 

[jasons2k]

Is it just me, or does the precip to the north appear to be holding together? What are they seeing that indicates it will fall apart?

[Kludge]

Is it just me, or does the precip to the north appear to be holding together? What are they seeing that indicates it will fall apart?

It sure didn't fall apart as it moved in here. Might have even built a little as it approached. 1" since 8:15.

My first measurable in over a month.

[tireman4]

Jason,

I was just thinking the same thing. Humm

[Katdaddy]

Wow. The radar is looking good for some well needed widespread rains.

[tireman4]

It seems HGX read our minds....lol...Here ya go, update from their Facebook page:

930AM Radar update - line of storms slowly moving south from College Station to Huntsville. Heavy rainfall will be possible with frequent lightning. Rainfall rates of 1 to 1.5 inches an hour will be possible in stronger storms. Travel along I-45 from north of Conroe to Centerville will be impacted. The storms could reach the Houston area towards the lunch hour but could weaken before reaching the area. Outflow from these storms could still be the focus for more storm development this afternoon across the Houston area.


https://www.facebook.com/US.NationalWea ... ov?fref=nf