JUNE 2015 -Scattered Showers/Storms To End The Month

[jasons2k]

The writeup already answers those questions in great detail.

[Paul Robison]

It is important to note that high perceptible water values by themselves don’t create thunderstorms (right?); they're just a key ingredient for them. You need something to spark all that moisture to turn into rain. That something is forcing. NOAA says that, although high pressure system currently over the region should break down this weekend, the forcing is not the strongest they've seen.

Bottom line: heavy rain over SE TX possible but not chiseled in stone.

[Texaspirate11]

It is important to note that high perceptible water values by themselves don’t create thunderstorms (right?); they're just a key ingredient for them. You need something to spark all that moisture to turn into rain. That something is forcing. NOAA says that, although high pressure system currently over the region should break down this weekend, the forcing is not the strongest they've seen.

Bottom line: heavy rain over SE TX possible but not chiseled in stone.

Hey Paul
Good evening I hope your enjoying this fine night.
Nothing in weather is ever chiseled in stone - that makes it exciting right?!
Even our wonderful HGX NWS states in their disco this evening they haven't quit pinned down where
the heaviest rainfall will be. I know they wish they could. They did mention S of 59 may have the impact.
For now.

You asked if you'd be safer on the coast or inland - from reading the information we have AT THIS MOMENT
(and you know things change) the coast may see the heaviest rainfall.

THIS IS WHY we ask everyone to always be prepared. I know some are tired of hearing it over and over again
And everyone wants definitive answers - (sometimes the 8 ball just doesn't work) but...you know that
another heavy rain event may come this weekend.

With that information that is out, you need to be prepared.
Don't go out in flooding waters
Make sure you have a plan to escape if you need to get out of an area that is beginning to flood
OR has a history of flooding
Make sure your valuables and important papers are up high enough to stay dry - if possible.

I know those in the Southwest of Houston were not expecting the horrific flooding they received just a short time ago.
I know I didn't expect the flooding Webster got in the beginning of May.
These kind of events you have to be prepared to the best of your ability.
No one has the definitive answer as to where EXACTLY the rain will fall - yet.

Just stay weather aware. And I do love your curiosity.

[Texaspirate11]

It is important to note that high perceptible water values by themselves don’t create thunderstorms (right?); they're just a key ingredient for them. You need something to spark all that moisture to turn into rain. That something is forcing. NOAA says that, although high pressure system currently over the region should break down this weekend, the forcing is not the strongest they've seen.

Bottom line: heavy rain over SE TX possible but not chiseled in stone.

Hey Paul
Good evening I hope your enjoying this fine night.
Nothing in weather is ever chiseled in stone - that makes it exciting right?!
Even our wonderful HGX NWS states in their disco this evening they haven't quit pinned down where
the heaviest rainfall will be. I know they wish they could. They did mention S of 59 may have the impact.
For now.

You asked if you'd be safer on the coast or inland - from reading the information we have AT THIS MOMENT
(and you know things change) the coast may see the heaviest rainfall.

THIS IS WHY we ask everyone to always be prepared. I know some are tired of hearing it over and over again
And everyone wants definitive answers - (sometimes the 8 ball just doesn't work) but...you know that
another heavy rain event may come this weekend.

With that information that is out, you need to be prepared.
Don't go out in flooding waters
Make sure you have a plan to escape if you need to get out of an area that is beginning to flood
OR has a history of flooding
Make sure your valuables and important papers are up high enough to stay dry - if possible.

I know those in the Southwest of Houston were not expecting the horrific flooding they received just a short time ago.
I know I didn't expect the flooding Webster got in the beginning of May.
These kind of events you have to be prepared to the best of your ability.
No one has the definitive answer as to where EXACTLY the rain will fall - yet.
But Srain has outlined extensively the ingredients involved and how it could all come together!

Just stay weather aware. But, I do love your curiosity.

[srainhoutx]

The overnight guidance continues to advertise a rather complicated and complex upper and lower level pattern emerging this weekend into early next week and possibly throughout most of the upcoming work week. Deep tropical moisture has been pooling across the NW Caribbean Sea and the Southern Bay of Campeche. Satellite derived data suggests PW's around 2.3+ inches are expected to begin lifting into the Western Gulf and reach the NW and Northern Gulf Coast around Friday and continue throughout the weekend into early next week. There are several features that should allow for the development of tropical showers and storms to increase during this time frame. A shear axis or the differential between the ridge to our East and a flattening ridge to our West increases the SE flow off the Gulf at the surface while a weakness between the two ridges develop aloft. The fly in the ointment will be two features upstream. A trough is expected to dig into Northern Mexico into the Southern Plains by Sunday into early next week. Newly formed Tropical Depression 3E is expected to slowly meander toward the Pacific Coast of Mexico and turn WNW skirting near the Coastline spreading mid and upper level moisture across Mexico. As the trough deepens to our West, the upper level winds may turn to a SW to NE flow aloft sending mid and upper level moisture into the Southern Plains and Texas early next week. Pressure falls are indicated across the Bay of Campeche and the Western Gulf continuing the long fetch South Easterly flow at the surface bringing additional tropical moisture toward the Texas and Louisiana Coast. Embedded disturbances in the SW upper flow from what may be Hurricane Carlos in the Eastern Pacific looks to spread along a frontal boundary across New Mexico, West Texas and the Panhandle into Oklahoma and on NE. The GFS and Euro have come into somewhat better agreement suggesting the upper ridge building across the SE United States may not push as far West as previously modeled leaving a weakness across the Lone Star State. These various features along with embedded mid upper level disturbances could provide the ' trigger' for heavy tropical showers and thunderstorms capable of dropping very heavy rainfall rates where they occur in the 2 to possibly 4 inch per hour range. The combination of all these features is why we are seeing the various National Weather Offices mentioning the possibility of heavy rainfall and possibly localized street flooding issues. Add to the mix any meso features that cannot be determined beyond 6 to 12 hours in advance and you have a recipe of forecasting challenges and uncertainties. It does appear that the benign dry pattern of the past 11 days is coming to an end and we will be back into Weather Watching mode again.

[srainhoutx]

Morning Update from the Weather Prediction Center for the Extended Range.

EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1158 AM EDT THU JUN 11 2015

VALID 12Z SUN JUN 14 2015 - 12Z THU JUN 18 2015

*** HEAVY RAINS POSSIBLE ALONG THE NORTH/NORTHWEST GULF COAST AND
ACROSS PORTIONS OF THE SOUTHERN PLAINS AND MIDDLE TO UPPER
MISSISSIPPI VALLEY ***


...PATTERN OVERVIEW...

ANOMALOUSLY STRONG RIDGING OVER SOUTHWEST ALASKA WILL DOMINATE THE
MID-LEVEL FLOW ACROSS THE CONUS STARTING THIS WEEKEND AND
CONTINUING THROUGH NEXT WEEK. SUBTROPICAL RIDGING ALONG 30N WILL
STRENGTHEN IN TIME ON EITHER SIDE OF MEXICO AND EVENTUALLY
OVERTAKE THE LOWER LATITUDES...FORCING THE MAIN STORM TRACK NORTH
THROUGH SOUTHERN CANADA AND STALLING ATTENDANT FRONTAL BOUNDARIES
OVER THE CENTRAL PLAINS...MIDWEST...AND NORTHEAST/NORTHERN
MID-ATLANTIC STATES.

...MODEL EVALUATION AND PREFERENCES...

MODELS ARE IN GOOD AGREEMENT WITH THE LARGE SCALE FLOW OVER THE
CONUS...BUT ARE STILL SHOWING VARIATIONS WITH SOME IMPORTANT
SMALLER SCALE DETAIL DIFFERENCES. ONE MAJOR CONCERN WILL BE WHERE
THE BREAK IN THE SUBTROPICAL RIDGE OCCURS IN THE LOWER
LATITUDES...WHICH WILL IMPACT WHERE THE HEAVIEST RAINFALL AXIS
SETS UP OVER THE SOUTH CENTRAL U.S.. IN GENERAL...THE ECMWF HAS
BEEN ON THE WESTERN EDGE OF MODEL SPREAD...WHILE THE GFS HAS
STAYED FARTHER EAST WITH THE BREAK. A SECONDARY CONCERN IS HOW
THE MODELS HANDLE INDIVIDUAL SURFACE WAVES DEVELOPING ALONG
FRONTAL BOUNDARIES STALLING FROM THE NORTHERN MID-ATLANTIC STATES
TO CENTRAL PLAINS.

...SENSIBLE WEATHER HIGHLIGHTS...

LOCATIONS ALONG THE NORTH/NORTHWEST GULF COAST AND ACROSS PORTIONS
OF THE SOUTHERN PLAINS AND MIDDLE TO UPPER MISSISSIPPI VALLEY WILL
BECOME VULNERABLE TO HEAVY RAINS AS ANOMALOUS MOISTURE GETS PULLED
NORTHWARD OUT OF THE GULF AND AROUND THE WESTERN SIDE OF THE RIDGE
EXPANDING OVER THE SOUTHEAST. DEPENDING ON THE EXACT TRACK/DEPTH
OF SURFACE WAVES DEVELOPING ON A LINGERING BOUNDARY STALLING OVER
THE NORTHERN PERIPHERY OF THE RIDGE...THE GREAT
LAKES...NORTHEAST...AND NORTHERN MID-ATLANTIC STATES COULD ALSO
SEE HEAVY RAINS. TEMPERATURES TO THE SOUTH OF THE STALLED
BOUNDARY MAY APPROACH THE 100 DEGREE MARK FOR MULTIPLE DAYS IN
PARTS OF GEORGIA AND SOUTH CAROLINA...WHICH WOULD BE CLOSE TO
RECORD HIGH VALUES.

[srainhoutx]

The 12Z GFS continues to advertise very impressive precipitable water values and rainfall totals through early Tuesday afternoon.

[srainhoutx]

The 12Z GEFS (GFS Ensembles) agrees with the operational solution suggesting some heavy rainfall potential into mid next week.

[Portastorm]

12z Euro looks equally wet and seems to open the Gulf for business by keeping a steady east-to-west flow of disturbances into SE Texas.

[srainhoutx]

The 12Z Suite of operational guidance has come into better agreement with the Euro, Canadian and the GFS generally suggesting an upper low currently along the Northern Gulf Coast near New Orleans will retrograde to the West ushering in deep tropical moisture from the Western Caribbean and the Bay of Campeche with a strong southeasterly onshore flow. It appears this pattern will continue throughout the weekend into early next week...at least. PW's suggested by the various computer schemes are very high and definitely tropical in nature with 2.3 to 2.5 inches of precipitable water being advertised. A trough to the West increases the onshore flow tomorrow and those impressive PW's surge NW into the Western Gulf as the upper low meanders W toward the Gulf Coast of Mexico this weekend.

Heavy rainfall rates are possible where thunderstorms develop and could be capable of dropping 2 to 3 inch per hour rainfall rates where they occur. Currently, Flash Flood Guidance is rather high due to the dry weather we've had the last 10 to 11 days, but flooding of the typical low lying areas and street ponding is certainly a possibility and will need to be monitored during the weekend into early next week.

[Texaspirate11]

HGX disco

RAINFALL AMOUNTS WILL BE TRICKY. USING US 59 AS OUR DIVIDER
BETWEEN THE HAVE AND HAVE NOTS OF RAINFALL...THINK NORTHWEST OF US
59 WILL LIKELY SEE 1-2 INCHES OF RAIN THROUGH MONDAY. SOUTHEAST OF
THERE LOOKS LIKE 2-4 MAYBE AN ISO 6 ESPECIALLY CLOSER TO WHERE THE
MOISTURE AXIS SETS UP OVER E TX. RAINFALL RATES IN INDIVIDUAL
STORMS WILL VARY AND HARD TO GET A GRASP UPON WITH PRECIP WATER
VALUES INCREASING TO 2.2 INCHES OVER THE WEEKEND. THE GFS REALLY
HITS MONDAY HARDER WITH PRECIP WATER VALUES 2.3 INCHES ALONG THE
COAST AND DEVELOPING QUITE A BIT MORE PRECIP THAN THE PREVIOUS
DAYS. RIGHT NOW LOOKS LIKE SINCE GROUNDS HAVE DRIED QUITE A BIT IT
WILL TAKE A GOOD 4-6 INCHES OF RAIN IN 3 HRS TO GET FLASH FLOODING
ACROSS THE AREA. THE AREA MIGHT COULD HANDLE THAT FRI/SAT/SUN BUT
MAY NEED TO KEEP AN EYE OUT FOR A FLASH FLOOD WATCH SUN GOING INTO
MON IF RAINFALL AMOUNTS MATERIALIZE. WATCH MAY EVEN BE LIMITED TO
SOUTHERN HALF OF THE FORECAST AREA.

[mckinne63]

Just had a heavy downpour in Stafford. Was strange as the sun was out and not alot of clouds in the sky. I also checked radar here and on transtar I didn't see anything. It didn't last long, about 5 minutes, but those rain drops were thick!

[Paul Robison]

Despite ongoing drainage from the last round of storms, the bayous should be in a position to handle another major rain event.

[Katdaddy]

Heavy tropical rains for the Upper TX Coast and SE TX continue to look possible beginning late tonight into next week as a surge of deep tropical moisture arrives from the NW Caribbean and GOM.

[srainhoutx]

No real change in the thinking over night regarding our sensible forecast for the weekend into early next week as Katdaddy mentioned in his post. There is something worth monitoring as a curiosity next week in the Southern Bay of Campeche as the various computer schemes are 'sniffing' an area of low pressure festering offshore near Veracruz, Tampico up to near Brownsville along the Western Gulf of Mexico. The GFS does have a elongated weak area of low pressure in that area while the Canadian develops a tropical storm in the Western Gulf and moves it onshore near Corpus Christi late next week. The Canadian solution is an outlier as it typically spins up every area of tropical thunderstorms into a cyclone, so let's not worry about that model. The European does have a very weak surface low in the SW Bay of Campeche next week, but never develops it.

The primary concern this morning is localized flooding potential as the upper low/trough S of Vermillion Bay meanders W toward Tampico and NE Mexico this weekend ushering in very high precipitable water values of 2.3 to 2.5 inches which is near record territory for the Texas and Louisiana Coast and the increasing winds and tides associated with the long fetch surge of very deep tropical moisture along the Middle/Upper Texas and SW Louisiana Coast.

[srainhoutx]

Well the 12Z GFS has thrown a bit of a curveball at us suggesting a weak tropical disturbance originating from the NW Caribbean moving NW over the weekend and nearing the Corpus Christi area early next week.

[srainhoutx]

The 12Z GEM (Canadian) is a bit faster moving the area of disturbed weather NW across the Western Gulf and has it approaching the Surfside area early Tuesday morning. Notice there are not any strong winds with this disturbed weather.

The attachment 06122015 12Z CMC 96 gem_mslp_pcpn_watl_16.png is no longer available

[srainhoutx]

Updated Extended Range Forecast Discussion from the Weather Prediction Center continues to advertise a heavy rainfall threat across our Region into next week.

EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1215 PM EDT FRI JUN 12 2015

VALID 12Z MON JUN 15 2015 - 12Z FRI JUN 19 2015

*** A HEAVY CONVECTIVE RAIN THREAT IS POSSIBLE FROM THE WRN GULF
COAST THROUGH THE PLAINS AND ACROSS THE MID-UPPER MS
VALLEY/MIDWEST/OH VALLEY AND INTO THE MID-ATLANTIC***

*** TEMPERATURES COULD APPROACH RECORD HIGHS OVER GEORGIA AND THE
CAROLINAS ***


...PATTERN OVERVIEW...

SUBTROPICAL RIDGING EXPANDING OVER THE SOUTHERN TIER OF THE NATION
EARLY NEXT WEEK WILL KEEP FRONTAL SYSTEMS CROSSING THE NORTHERN
U.S. FROM PRESSING INTO THE LOWER LATITUDES...RESULTING IN A
STALLED FRONTAL BOUNDARY EXTENDING FROM THE CENTRAL PLAINS TO THE
NORTHERN MID-ATLANTIC COAST. A CLOSED LOW OFF THE BRITISH
COLUMBIA COAST SHOULD BEGIN TO SINK SOUTH TOWARDS THE MIDDLE OF
NEXT WEEK AND COULD EVENTUALLY LEAD TO MEAN TROUGHING OVER THE
WESTERN U.S. BY LATE NEXT WEEK.


...MODEL EVALUATION AND PREFERENCES...

DETERMINISTIC GUIDANCE HAS COME INTO GOOD AGREEMENT WITH THE MEAN
FLOW OVER THE CONUS THROUGH THE MIDDLE OF NEXT WEEK...BUT THE
DETAILS OF THE FORECAST BECOME VERY UNCERTAIN BY NEXT THURSDAY AND
FRIDAY. MODELS ARE STILL SHOWING VARYING SOLUTIONS WITH WHERE A
POSSIBLE BREAK IN THE SUBTROPICAL RIDGE SETS UP OVER TEXAS...AND
ARE ALSO DIVERGING WITH THE EVOLUTION OF THE CLOSED LOW SINKING
SOUTH FROM THE BRITISH COLUMBIA COAST.

THE WPC FORECAST RELIED ON A BLEND OF THE AGREEABLE 00Z GFS/ECMWF
FOR THE DAY 3-4 FORECAST...BUT THEN TRANSITIONED TO ENSEMBLE MEAN
GUIDANCE BY DAY 5 IN ORDER TO ACCOUNT FOR THE UNCERTAINTY.


...SENSIBLE WEATHER HIGHLIGHTS/THREATS...

THE WESTERN GULF COAST AND INLAND ACROSS PORTIONS OF THE PLAINS
AND MID-UPPER MISSISSIPPI VALLEY WILL REMAIN VULNERABLE TO HEAVY
RAINS EARLY NEXT WEEK AS ANOMALOUS MOISTURE CONTINUES TO GETS
PULLED NORTHWARD OUT OF THE GULF AND AROUND THE WESTERN SIDE OF
THE RIDGE EXPANDING OVER THE SOUTHEAST. DEPENDING ON THE
TRACK/DEPTH OF ANY SURFACE WAVES AND PERIODIC EPISODES OF
CONVECTION DEVELOPING NEAR LINGERING BOUNDARIES STALLING OVER THE
NRN PERIPHERY OF THE RIDGE...THE MIDWEST/GREAT
LAKES...NORTHEAST...AND NRN MID-ATLANTIC STATES COULD ALSO SEE
HEAVY RAINS. BENEATH THE MAIN RIDGE ALOFT...TEMPERATURES COULD
APPROACH RECORD HIGHS ACROSS GEORGIA AND THE CAROLINAS.


GERHARDT

[srainhoutx]

The National Hurricane Center is now monitoring the disturbance that the computer models have been suggesting may develop over the weekend into early next week in the Western Gulf of Mexico.

06122015 2PM EDT two_atl_5d0.png

TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
200 PM EDT FRI JUN 12 2015

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

1. Disorganized showers and thunderstorms extending from the
northwestern Caribbean Sea to Belize and the Yucatan peninsula of
Mexico are primarily associated with an upper-level trough. This
activity is expected to move northwestward into the southwestern
Gulf of Mexico by late Sunday where development, if any, is unlikely
due to strong upper-level winds.
* Formation chance through 48 hours...low...near 0 percent
* Formation chance through 5 days...low...10 percent

Forecaster Blake/Franklin

[srainhoutx]

The 12Z European also suggests a possible area of distributed weather nearing Brownsville to Corpus Christi next Tuesday.