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View Full Version : Rainy Pattern Continues.....7/19/07


ticka1
07-19-2007, 08:32 AM
Latest update from Jeff Lindner:
Another day no change as wet pattern remains locked in place and will continue for many days.

Area radars are already very active this morning as deep tropical moisture streams into the region from the SE. Rainfall this morning so far is already pushing 2.0-3.0 inches over Jackson and Calhoun counties with numerous thunderstorms extending from W Galveston Island to Matagorda County moving northward. PWS of 2.1-2.3 inches along with low trigger temperatures will result in numerous thunderstorms off and on through mid afternoon. By mid to late afternoon storms should have become numerous enough to overturn the air mass and stabilize things. Main threat will be heavy rainfall with high PWS and nearly saturated air column. Good news is that storm motions are moving at 15-20mph so unless training occurs rainfall totals should remain in the manageable 1-2 inch range.

No change Friday as area remains locked in moist SE flow up to 8,000-10,000 ft with PWS averaging around 2.0 inches…hence another round of thunderstorms. Forecast for the weekend shows hints of drier air and slight ridging building into the area however this will likely only raise trigger temps. into the low 90’s and delay thunderstorms until the afternoon hours instead of the mornings. Will continue with a 40-50% chance through the weekend.

Next Week:

Upper pattern repeats next week as yet another upper trough axis breaks off from the main flow and settles into TX. Deep slug of tropical moisture looks to arrive in the Mon-Tue timeframe and widespread rains will once again be expected. In fact long range models are showing little drying or typical summer weather for the next 14 days.

Tropics:

No areas of concern at the moment. Global model trends are suggesting the potential for some developments over the next two weeks as we begin to move into the active time of the Atlantic basin hurricane season.

ticka1
07-19-2007, 11:24 AM
Latest from JeffL:

Urban Flood Advisory issued until noon for Harris County.

Intense line of excessive rainfall moving northward across Harris County with secondary line approaching from the south. ALERT rainfall gages show 15 minute rainfall rates of .7 to .9 of an inch over the Clear Lake area. Rainfall amounts of 1-2 inches in less than 1 hour is likely leading to rapid street flooding. Rainfall amounts since 900am have averaged 1.5-2.0 inches around Clear Lake N into the E side of downtown Houston.

An additional 1-2 inches of rainfall is likely over the next 1-2 hours.

ticka1
07-19-2007, 11:25 AM
Flood Advisory
National Weather Service Houston/galveston Tx
1006 Am Cdt Thu Jul 19 2007

Txc201-191700-
1006 Am Cdt Thu Jul 19 2007

The National Weather Service In League City Has Issued An

* Urban And Small Stream Flood Advisory For...
Harris County...

* Until Noon Cdt

* At 1006 Am Cdt...national Weather Service Doppler Radar Indicated
Thunderstorms Producing Heavy Rainfall Across The Houston
Metropolitan Area...extending Southeastward To Clear Lake And
Pasadena. Rainfall Amounts Of 1 To 3 Inches Are Likely In This Area
Through Noon.

Minor Flooding Is Likely In Or Near...
Metro Houston Area...
Clear Lake...
Pearland...
South Houston...
Aldine...
Bellaire...

Excessive Runoff From Heavy Rainfall May Cause Flooding Of Land
Adjacent To Creeks And Bayous...drainage Areas And Low Lying Spots.
Additionally...flooding May Occur On...streets...frontage Roads...and
Highway Underpasses. Avoid Locations Where Water Covers The Ground!

Please Report Flooding To The County Sheriff...local Police...or
Department Of Public Safety. They Will Relay Your Report To The
National Weather Service

archergirl66
07-20-2007, 08:15 AM
Got this from Jeff. One word: YUCK!




Our daily rains got going early today with widespread coverage already this morning. Parts of the county have already picked up 1-2 inches this morning leading to street flooding problems. Additional storms are firing off along the coast and will spread inland through the mid to late morning. Wet pattern will remain anchored over the area through Saturday as PWS remain over 2.0 inches and trigger temps. stay around the low to mid 80’s. Trigger temps. on Saturday may rise slightly suggesting a later start to the madness (maybe 1100-100pm) instead of in the morning. We may see a slight amount of drying Sunday with a reduced rain chance, but chances are on the rise for all of next week…in fact next week looks very unsettled as the tropics come into play.



Scattered storms should result Monday through Wednesday before a strong tropical wave currently over the E Caribbean Sea enters the Gulf of Mexico and heads for the TX and Mexican coasts late next week. GFS is forecasting a surge in tropical moisture late Wednesday with PWS rising to near 2.45 inches suggesting a nearly saturated air column. Clearly this will be of concern with the threat for excessive rainfall. Would also not totally discount the potential for some development of this wave as it moves through the Gulf of Mexico even though global models are not forecasting such.



Note:

It has rained every day in Harris County since July 1st and 17 out of the last 20 at IAH. The wet period began around June 14th and out of those 36 days, 27 have had measurable rainfall. The Jan –July 19th period is the 7th wettest period on record for that time frame with a total of 37.07 inches falling. IAH has recorded 6.99 inches of rainfall so far for July which is well above average. The wettest July on record occurred in 1900 with 14.80 inches of rainfall.



Tropics:

Overall pattern change in the upper air flow appears at least possible over the next 1-2 weeks. Deep troughing along the US E coast should lift out and be replaced with large scale ridging extending from the E Atlantic all the way into the Gulf of Mexico. This shifts the threat area and tracks of any tropical cyclones toward the west and the Gulf of Mexico. Main question is how long this pattern will remain locked in place and will there be anything in the tropics while the Gulf is vulnerable. Such patterns can lock into place for months, and if this is the case, will not bode well for the US Gulf coast as we head into the active months of hurricane season.