October 2014: Slight Rain Chances/Halloween Outlook

[unome]

an interesting post from Levi Cowan

http://youtu.be/sN8qnUBGlRk

Published on Oct 18, 2014

Website: http://www.tropicaltidbits.com/

A tidbit from the tropics by FSU meteorology grad student Levi Cowan. Levi has been tracking tropical systems closely since 2002, and has a bachelor's degree in applied physics with a concentration in atmospheric

[srainhoutx]

93L has been designated in the Bay of Campeche near the Tampico/Veracruz area. This sub/extratropical disturbance will have no effect on our weather other than perhaps some higher tides and elevated NE breezes near the Coast. The Florida Keys and S Florida could see some squally weather later this week.

[srainhoutx]

Dry and comfortable weather continues across our Region and I see no real change in the general pattern until the end of October. Typically we get these Chamber of Commerce weather days this time of year before the pattern begin to change in November. There are hints that as we begin the month of November we may see another pattern change that could bring to rain and colder air from Canada. Enjoy these cool morning and comfortable afternoons while they last.

[Kingwood32]

I'm ready for colder air!!!

[srainhoutx]

The dry pattern continues into the weekend, the changes lurk as we end October. It appears a storm system (short wave will cross Texas next Tuesday bringing a cold front and hopefully some rain.

Bigger changes look to be ahead as we end October when the zonal flow off the Pacific Ocean transitions to a build Ridge over Alaska and a deep trough begins to slowly take shape across the Great Basin into the Rockies. Cold air begins to drop S as November begins and there are indications that our first 'Blue Norther' of the Fall Season may march across our Region with temperatures tumbling into the low 40's across Coastal Texas and 20's to 30's elsewhere across the Lone Star State. That would be during early November and another Topic should it verify.

[cperk]

The dry pattern continues into the weekend, the changes lurk as we end October. It appears a storm system (short wave will cross Texas next Tuesday bringing a cold front and hopefully some rain.

Bigger changes look to be ahead as we end October when the zonal flow off the Pacific Ocean transitions to a build Ridge over Alaska and a deep trough begins to slowly take shape across the Great Basin into the Rockies. Cold air begins to drop S as November begins and there are indications that our first 'Blue Norther' of the Fall Season may march across our Region with temperatures tumbling into the low 40's across Coastal Texas and 20's to 30's elsewhere across the Lone Star State. That would be during early November and another Topic should it verify.

I hope it does verify i am ready for some cold weather.Thanks srainhoutx.

[Texaspirate11]

From the HGX NWS concerning NOVEMBER and El NINO

The outlook for November from the Climate Prediction Center (CPC) shows that probabilities favor slightly above normal rain chances for Southeast Texas as a weak El Nino event develops this winter. Probabilities with regard to the temperature forecast are less clear and there are equal chances of above, near normal or below normal temperatures. Parts of Southeast Texas remain very dry and could use the extra rainfall. At this time, it looks like 2014 rainfall will be below normal. If this occurs, it will be the sixth consecutive year with below normal rainfall across Southeast Texas. Houston Hobby was suffering a 2014 rainfall deficit of 12.23 inches. The 2014 rainfall at Galveston was 17.32 inches below normal and at the NWS office in League City, the 2014 rainfall deficit was 9.65 inches.

[srainhoutx]

I do not see a lot of changes in the forecast into next week. As some have heard, there were some issues with the satellite data being available for all the computer models over North America including the non American guidance. That issue was corrected yesterday, so we should see the guidance begin to perform a bit better over the next several cycles. It does appear a front will push across the Region mid next week and that looks to set the stage for shorter wave lengths and an amplified flow (deep trough) and reinforcing shots of colder air to end October. Halloween could be breezy and a bit chilly as the next front arrives. It still appears a stronger push of colder air arrives the first week of November and daytime temperatures may struggle to get out of the upper 50's to low 60's.

[srainhoutx]

Morning briefing from Jeff:

Fairly impressive streak of nice weather has been ongoing across the region for the last week and a half with a dry air mass in place resulting in 50’s for lows and 80’s for highs with low RH.

High pressure at the surface over the eastern US with a building upper level high over the SW US will result in gradually warming temperatures over the next 48 hours. Could see a few locations approach 85-90 degrees over the weekend, but humidity values will remain low for coastal TX standards.

Moisture appears to finally begin to make a more sustained comeback to the region Monday as winds finally return to onshore. An upper level storm system will move into the western US early next week which should transition the upper flow to increasingly SW aloft. Gradual moisture increase will allow rain chances to come back into the forecast by Tuesday as a few showers stream inland off the Gulf. Long range global models are not in great agreement on when and how strong a cold front will cross the area mid to late week. Currently looking at a fairly strong frontal passage Thursday with a chance of showers and thunderstorms. Post frontal air mass late next week looks dry and cool with a period of strong gusty winds possibly next Friday. Timing is still in question so some changes in the Tuesday-Friday period is likely with respect to rain chances and temperatures.

[Paul Robison]

Morning briefing from Jeff:

Fairly impressive streak of nice weather has been ongoing across the region for the last week and a half with a dry air mass in place resulting in 50’s for lows and 80’s for highs with low RH.

High pressure at the surface over the eastern US with a building upper level high over the SW US will result in gradually warming temperatures over the next 48 hours. Could see a few locations approach 85-90 degrees over the weekend, but humidity values will remain low for coastal TX standards.

Moisture appears to finally begin to make a more sustained comeback to the region Monday as winds finally return to onshore. An upper level storm system will move into the western US early next week which should transition the upper flow to increasingly SW aloft. Gradual moisture increase will allow rain chances to come back into the forecast by Tuesday as a few showers stream inland off the Gulf. Long range global models are not in great agreement on when and how strong a cold front will cross the area mid to late week. Currently looking at a fairly strong frontal passage Thursday with a chance of showers and thunderstorms. Post frontal air mass late next week looks dry and cool with a period of strong gusty winds possibly next Friday. Timing is still in question so some changes in the Tuesday-Friday period is likely with respect to rain chances and temperatures.

Will we have any strong/severe t-storm potential with this "fairly strong" front, Jeff?

[Katdaddy]

Mostly sunny today with increasing moisture levels. Rain chances increase later in the week as our next cool front moves across TX. This front will give TX another weekend of perfect weather.

[Paul Robison]

Mostly sunny today with increasing moisture levels. Rain chances increase later in the week as our next cool front moves across TX. This front will give TX another weekend of perfect weather.

Dear--whoever:

Houston area weather discussion has me worried:


DISCUSSION...
THE UPPER LEVEL RIDGE THAT HAS BEEN OVER SE TX HAS BEGUN TO BREAK
DOWN WITH AN UPPER TROUGH MOVING INTO THE PLAINS. A PACIFIC FRONT
WILL MOVE THROUGH SE TX ON WEDNESDAY WITH A COLDER AIRMASS
ARRIVING BY FRIDAY. THE MAIN FORECAST ITEMS OF CONCERN WILL BE
CHANCES FOR RAIN FOR TUESDAY THROUGH THURSDAY...AND THEN THE
TEMPERATURE FORECAST LATE THIS WEEK INTO EARLY NEXT WEEK.

THE FIRST ITEM FOR LATE THIS AFTERNOON REGARDS ISOLATED STREAMER
SHOWERS MOVING INLAND EAST OF FREEPORT. DECIDED TO KEEP THE POPS
AT 10 PERCENT BUT MENTION ISOLATED RAIN SHOWERS IN THE GRIDDED
DATA THROUGH 7 PM FOR THE COASTAL WATERS...AND PORTIONS OF THE
INLAND AREAS EAST OF INTERSTATE 45 TO AROUND INTERSTATE 10. THESE
WILL NOT SHOW UP IN THE COUNTY FORECAST TEXT PRODUCT BUT WILL IN
THE POINT AND CLICK FOR THE LATE AFTERNOON PERIOD.

OTHERWISE...THE PREVIOUS RAIN FORECAST LOOKED TO BE FAIRLY ON
TRACK. EVEN WITH A SOMEWHAT FAVORABLE JET PATTERN ALOFT...THE
GFSBUFR MODEL FORECAST SOUNDINGS SHOW A CAP MAY BE TOO MUCH OF A
PROBLEM TO OVERCOME FOR ANY BUT ISOLATED THUNDERSTORM DEVELOPMENT
AHEAD OF THE COLD FRONT LATE TUESDAY AND EARLY WEDNESDAY. THE
MODELS ALSO HANG THE FRONT UP BEFORE REACHING THE COAST. BEHIND
THIS SYSTEM A SHORTWAVE TROUGH WILL MOVE THROUGH LATE WEDNESDAY
INTO THURSDAY. THE GFS AND ECMWF BOTH BRING THE LEFT-FRONT
QUADRANT OF A WEAK UPPER LEVEL JET OVER SOUTH TEXAS. THIS MAY BE
ENOUGH TO BRING ANOTHER CHANCE OF THUNDERSTORMS TO SE TX ON
THURSDAY.


Anyone have any opinions on what this all means? Will isolated sea-breeze rotating severe t-storm cells be possible even though the LFQ of the upper-level jet is weak? Will T-storms pack intense cloud-to-ground lightning? Wouldn't ask, but I've always heard the LFQs of a land-based shortwave are dangerous because they produce the strongest storms. Should I be worried?

[srainhoutx]

A cold front is near the Dallas/Ft Worth area this morning and should stall near the Temple/Waco area later today. The atmosphere remains capped so little in the way of rainfall outside of some light streamer showers moving inland off the Gulf is expect into Wednesday. A strong upper air disturbance is expected to drop SE across the Plains on Thursday and energize the cold front with a push of colder air by Thursday afternoon and push the front to the Coast. There is an isolated chance for a skinny line of showers and a storm or two to fire along the frontal boundary, but not much more than a 10th to a quarter of and inch of rain is expected. A powerful upper low near the Great Lakes should send a surge of colder air S on Friday with dry and breezy conditions expected for Halloween. As a note...Houston has not seen low temperatures drop into the 40's during October. The last time low temperatures failed to drop into the 40's in October was 2004. Many will recall that the following December brought the infamous Christmas Eve snow miracle from Brownsville to SW Louisiana with snow recorded all the way to the beaches along Coastal Texas. That just goes to show that Fall has just started and who knows what winter will bring as a Weak El Nino pattern continues to develop...

[Kingwood32]

A cold front is near the Dallas/Ft Worth area this morning and should stall near the Temple/Waco area later today. The atmosphere remains capped so little in the way of rainfall outside of some light streamer showers moving inland off the Gulf is expect into Wednesday. A strong upper air disturbance is expected to drop SE across the Plains on Thursday and energize the cold front with a push of colder air by Thursday afternoon and push the front to the Coast. There is an isolated chance for a skinny line of showers and a storm or two to fire along the frontal boundary, but not much more than a 10th to a quarter of and inch of rain is expected. A powerful upper low near the Great Lakes should send a surge of colder air S on Friday with dry and breezy conditions expected for Halloween. As a note...Houston has not seen low temperatures drop into the 40's during October. The last time low temperatures failed to drop into the 40's in October was 2004. Many will recall that the following December brought the infamous Christmas Eve snow miracle from Brownsville to SW Louisiana with snow recorded all the way to the beaches along Coastal Texas. That just goes to show that Fall has just started and who knows what winter will bring as a Weak El Nino pattern continues to develop...

I lived in Freeport in 04 and that Christmas snow was AMaZING!

[srainhoutx]

The weak frontal boundary just passed NW Harris County with light N to NE winds.

[BlueJay]

We are currently at 73F with light wind. My oh my-I must say it is cloudy and a bit dreary.
The front cometh.

[srainhoutx]

Morning briefing from Jeff:

Strong cold front will cross the area Friday morning ushering in some of the coldest temperatures this fall.

Weak frontal boundary that pushed offshore yesterday evening has stalled over the Gulf waters with light NE winds in place across SE TX this morning and temperatures in the 50’s and 60’s. Low level moisture has been pushed southward with this boundary. Strong short wave trough over the northern US is allowing a cold Canadian air mass to surge southward from Canada this morning. Current temperatures in the northern plains behind this front are in the 30’s (34 at Bismark, ND currently) and this air mass will pour southward today and spread across Texas early Friday in a modified form. Short range models continue to suggest some 850mb moisture will surge northward this afternoon across central TX and the western portions of SE TX and actually are producing showers and thunderstorms with the boundary late tonight into early Friday morning west of I-45. Given the increasing potential in the short term guidance this seems at least possible even though surface moisture will be lacking. Out of respect of the meso guidance rain chances of 30% will be added to the areas west of I-45 for late tonight. Texas Tech guidance is fairly aggressive overnight with a band of thunderstorms that moves SSW from NCT X across much of central and western SE TX into S TX.

Front should clear the coast by 900am with cold air advection and gusty north winds in place on Friday. Skies will rapidly clear, but even under full sun cold air advection should offset surface heating and highs will only reach the low to mid 70’s on Friday.

Halloween Evening:
Excellent conditions for all outdoor activities with temperatures falling from near 70 around 600pm into the low 60’s and upper 50’s by 1000pm under weakening north winds, clear skies, and low humidity values. Sunset is 636pm.

Weekend weather will be extremely nice by SE TX standards. 1036mb Canadian high pressure cell will build into TX resulting in cool to cold morning lows and mild afternoon highs under sunny skies. Guidance has been trending cooler with the incoming air mass and this appears reasonable given the observations in the northern plains. GFS guidance shows a low of 44 at IAH Sunday morning and 36 at the normally cold Conroe reporting station. Will go with lows in the mid to upper 40’s Saturday morning and low to mid 40’s Sunday morning with highs on Saturday likely not making it out of the 60’s as weak cold air advection continues.

Note: A reminder that daylight savings time ends this coming Sunday morning with clocks falling back one hour at 200am. Sunset Sunday evening will be at 534pm.

Next Week:
Models continue to struggle greatly with the evolution of the weather pattern next week and when and how strong of a trough will affect the state. GFS is more progressive then the slower ECMWF solution, but both agree that a significant increase in moisture is heading for the state starting Monday. This is in part to tropical depression 21E which should intensify to Hurricane Vance south of MX this weekend and turn N and NNE and become captured by a very deep trough early next week over the SW US and northern MX. NHC forecast brings a 80mph hurricane toward the SW Mexican coast in 5 days. Mid and high level moisture from Vance will pour NNE into TX aloft while at the surface strong moisture advection will occur off the Gulf of Mexico. The result appears to be surging PWS values to near/above 2.0 inches which is extremely high for early November. In fact 2.0 in PW for early November is at the 99th percentile and at the +2Sd above normal for the Corpus Christi sounding station. A slow moving surface front combined with disturbances ejecting out of the mean trough to our west and possibly out of the moisture envelop from Vance working on a saturated air mass with upper level flow near parallel to the front supports a heavy rainfall and potential flooding threat. Big question is does this come in one significant round of storms and when or is it spread out in repeat rounds from a slower moving upper trough. Concern is certainly there for some significant rainfall next week at some point in the Tuesday-late week time period with the Tuesday-Wednesday period looking most likely. Once guidance begins to fall into better agreement rain chances will need to be raised significantly for the favored time period.

21E Guidance Tracks:

10302014 06z TD 21 Jeff Image 1 unnamed.jpg

[srainhoutx]

The secondary and stronger cold front is moving a bit faster than expected. Scattered storms are developing along the front W of Ft Worth and our Western areas may see some brief rain with rumbles of thunder over night. This stronger push of colder likely will push off the Coast early tomorrow morning. Temperatures behind the front are cooler than previously expected and we may see some upper 40's tomorrow night for those Halloween festivities.

[Katdaddy]

Another perfect TX weather weekend begins on this Halloween day as the second cool front is moving into N portions of SE TX and will be off the coast later this morning bringing very low humidity in the 20s. Lows will be down right scary this evening in the upper 40s.

[BlueJay]

Happy Halloween everyone!