October 2015 - Severe Storms/Moderate Risk Excessive Rainfal

[srainhoutx]

Morning briefing from Jeff:

More humid and warmer conditions to return this week.

US upper air pattern remains mostly blocked with deep low pressure over the SE and SW US and high pressure over the central and southern plains. This has resulted in our locally very nice weather over the last 3 days while the US SE coast has seen some incredible rainfall amounts and flooding (see below). Upper air pattern will slowly begin to unblock as the large scale system over the SE US moves offshore and the SW US system over S CA this morning begins to move eastward over the desert SW. Changes over SE TX will be slow with gradual warming and then slow moistening over the atmosphere as winds turn out of the ESE and SE by mid to late week.

After Wednesday the SW US upper level system will begin to approach TX from the west, but latest guidance is not allowing this system to progress as far eastward as in previous runs and keeps the best dynamics and moisture across western and southwestern TX and mainly W of SE TX. This will focus the heaviest rainfall over west TX with a low level feed of moisture inland over the coastal bend and then WNW to NW into central and W TX. Will go with the highest rain chances over our western and southwestern counties Thursday and Friday (20-30%) with the lowest rain chances over our eastern counties. There is still some uncertainty in this part of the forecast so some changes might be needed toward the end of the week into this weekend.

SC Flooding:
Impressive upper level storm system over the SE US combined with moisture feed from Hurricane Joaquin to produce a period of incredible rainfall over the state of SC this weekend. Additionally, long fetch ENE to E winds resulted in significant coastal flooding and storm surge…some of the highest since Hurricane Hugo (1989). Tides rose to 8.3 ft MLLW at Charleston Harbor on Saturday morning resulting in overwash of the protective seawall and flooding of portions of the city. Inland areas between Charleston and Columbia recorded 15-25 inches of rainfall over the weekend with 10-15 inches falling overnight Saturday into Sunday morning. Rainfall frequency curves for this region indicate between a 500-yr and 1000-yr rainfall amounts.

A few selected rainfall amounts (48-hr storm totals):

3 NE Boone Hall Plantation: 26.88
Gills Creek: 20.28 (16.61 inches in 24 hours)
Millwood: 20.75
Shadowmoss (N Charleston): 23.51
Downtown Charleston: 16.02
Charleston Airport: 17.29

[BiggieSmalls]

Looks like no real fall weather on the horizon in the next two weeks (unless you consider lows in the high 60s and highs around 85 "fall)...The summer that just won't go away....

[Katdaddy]

Increasing high clouds will lead to slight rain and thunderstorm chances by Thursday as the upper level low over the SW US drifts E. The upper level low is forecast to then retrograde back W during the weekend ending the rain chances but increasing heat and humidity.

[Katdaddy]

Partly sunny skies today and Thursday followed by a slight chance of thunderstorms Thursday night through Friday afternoon. A weak cool front arrives Friday night with drier air for the weekend, as well as; slightly lower temps.

[Katdaddy]

A weak disturbance will bring a chance of showers this afternoon through Friday night. A cool front to arrives tomorrow evening and will give SE TX a nice mostly sunny weekend with slightly cooler temps.

[Cromagnum]

Everything about the Houston weather has been bad this year. Feet of rain in the spring followed by 6+ months of summer. I dont think we are actually even going to get a fall this year.

[ticka1]

it will probably go straight to freezing weather when the change does happen.

[sambucol]

it will probably go straight to freezing weather when the change does happen.

I'll take it!!!

[jasons2k]

I don't mind the warm weather, but we could sure use some rain. Even with the spring rains, these mini-droughts we keep having have killed off another round of trees still under stress. It looks like the fall leaves won't have much color this year - they tend to just turn brown and fall off when it's dry like this.

[wxman57]

Here's a meteogram I made off the 6Z GFS. Cold front moves through Tuesday morning but doesn't impact the highs much. A lot drier air by Wednesday and cooler morning lows, though.

[snowman65]

92 on Oct 19...lol...BBBRRRRR...Bundle up folks!

[snowman65]

I call hogwash on this....

http://www.weather.com/tv/shows/amhq/vi ... for-winter

[DoctorMu]

El Niño years that run dry and warm in Sept - Oct often flip in November. We'll see...

[srainhoutx]

The weekly Update of the new experimental Climate Prediction Center Week 3 to 4 Outlook does tend to suggest once we near the end of October and begin November, perhaps some changes evolve in this persistent boring weather pattern. Updates are issued every Friday for this new Experimental CPC Week 3 to 4 Product.

[TxLady]

I'm so thankful that last Saturday's weather was absolutely perfect for my get-together. But, I'm really starting to wonder if/when the much advertised pattern-change will begin. We need some rain. The cooler temps have been sneaking in; but, there hasn't been much moisture. After the Spring we had, I would've never imagined that we'd be begging for some rain.

[jasons2k]

It's getting really dry. I also can't believe it after the spring we had and El Niño continuing. Like I've pointed out before, tree stress is a long term and cumulative thing. A couple of wet months isn't an instant cure. We really need a couple of wet years to get things back to normal.

[jeff]

A warm Atlantic (note the impressive warming since June) and a continued warm Gulf of Alaska region support southern plains drought...ie same pattern we have been in for years. Big question is can El Nino overwhelm this pattern and bring wet weather to Texas.

On a side note...conditions for the 2016 hurricane season in the Atlantic are starting to look very favorable with extremely warm SST's and below average wind shear as El Nino wanes by next summer. These warm SST's in the Atlantic is one region we have had so many named storms this season even in the face of the generally unfavorable El Nino conditions. The Atlantic is giving us hints of what is to come.

[redneckweather]

Quick question Jeff (since nothing in our weather world is going on). You state, "can El Nino overwhelm this pattern and bring wet weather to Texas." I thought we are currently in an El Nino pattern which will be leading into a cold n wet late fall/winter season? That is what I hear all the forecasters saying. Are you saying we are NOT presently in am El Nino weather pattern but still in a drought weather pattern? It's either one or the other. Just looking for clarification on the current pattern we are in which I thought was an El Nino pattern. Thanks.

[srainhoutx]

The latest 12Z guidance suggests more of the same. The longer range data suggests the 'possibly' a bit of unsettle weather if the Central and Eastern Pacific cooperates for Texas. We will see.

[Katdaddy]

Shower and thunderstorm chances look a little better with the frontal passage beginning late tonight and Tuesday with a 30-40% chance across SE TX and the Upper TX Coast. Beginning Wednesday its more sunny skies, low humidity, and slightly lower temps with highs in the mid 80s and lows in the mid 60s through next weekend.