JUNE 2018: Drying Trend & Summer Heat Returns

[jasons2k]

Just took a look at some satellite loops. You can see the outflow of the Yucatan system (92L-to-be?) is spreading all the way to the Florida peninsula, but definitely asymmetrical to the east, indicating a lot of shear.

I would expect the center to have reformations to the NE over time and the bulk of the rains to the north and east of the center.

[Andrew]

GFS coming in more over SE Texas versus southern Texas which makes sense since it doesn't develop a closed low. Looking at expected shear levels over the northwest gulf while there may be periods of low shear and quick development it doesn't last too long on Sunday night. I think the latest solution from the GFS is actually pretty reasonable.

[don]

The 0z CMC is not backing down on development to what looks to be a depression.FWIW the CMC has been the most consistent model the last couple of days. The RGEM also tries to develop the system right before landfall along the upper Texas coast.Fwiw the ICON model also looks similar to the CMC.
https://www.tropicaltidbits.com/analysi ... cus_14.png

[don]

It seems like the Texas Tech WRF develops the system also.

http://www.atmo.ttu.edu/bancell/real_ti ... st_f48.gif

http://www.atmo.ttu.edu/bancell/real_ti ... bz_f48.gif

[brooksgarner]

How many inches? Got your attention. If consensus models (averaged separate models) like ICON (see tropicaltidbits.com) are even remotely accurate, the rainfall timing will change by 24hrs delay (M-T instead of S-M) plus totals would go up significantly. Will be interesting to track training potential but as far as making a call it’s obviously too chaotic right now with the developing future 92L to do more than explore various solutions. The potential is certainly there. Hopefully it doesn’t all come together. I’m purposely not posting the images from ICON’s 00z run for fear they’ll be taken out of context by a person who doesn’t understand that it’s not an actual forecast. I’ve heard by a person at NHC that consensus models are weighted seriously, approaching the consideration of ensembles. (The shortcomings of ‘icon’ for example is the culmination of its specific models used: DSHP, LGEM, GHMI, HWFI.) Thoughts??

[Andrew]

I'm suspect of ICON's rapid breakdown of ridging over the southeastern united states. Allows for the northeast/eastnortheast movement of the coastal low which no other model shows.

FWIW ECMWF shows a vort max racing across SE Texas but has the greatest development south of the border where eventually a system does develop and makes landfall along the Northern Mexico coastline.

[redneckweather]

My thoughts on the ICON? That is a "Harveyesque" load of rain in some parts of Southeast, Texas...especially along the coast, where I will be tomorrow thru next Friday (Galveston). Yea, I wouldn't post those images from the ICON either. Either way you cut it, looks like I might get a little wet while on vacation. lol

[srainhoutx]

First visible shot of the morning. I've been doing this for many years and for the life of me this thing has that look and certainly has more convection than 91L ever had. Why this isn't Invest 92L is beyond me. And every 24 hour we move back before this mess moves toward Texas, the more condition aloft and at the surface as well as the QPF expected are going to change.

[unome]

KHOU article, something to keep in mind: https://www.khou.com/article/news/local ... -564789563

snippet: A recent study by the UT Health Center finds 18 percent of Harris County residents -- which is more than 800,000 people -- are dealing with serious psychological distress linked to Hurricane Harvey.

it's been almost 20 years since our last home flooded for the 1st time and I still get anxiety. I have to say though, discussing the weather with knowledgeable people, like this board helps facilitate, really helps

[srainhoutx]

Saturday morning briefing from Jeff:

Rainfall chances…some heavy…increasing over the next 24-48 hours.

Yucatan/southern Gulf of Mexico tropical wave continues to show signs of life this morning with a large mass of deep convection having developed over the eastern Yucatan and the southern Gulf of Mexico. However, even though the satellite images may look impressive…there is no defined low level circulation and the wave is interacting with a mid/upper level trough over the SW Gulf of Mexico which is helping to vent the current convection. Large mass of high PW air (2.1-2.6 inches) is currently moving NW well ahead of the main convective area and now reaching the central Gulf and will be moving into the NW Gulf later today. This air mass will spread into coastal TX and LA on Sunday and remain in place through Tuesday.

Scattered showers and thunderstorms today will become scattered to numerous on Sunday with multiple waves of activity moving inland from the Gulf of Mexico. Time period is now moving within the better short term guidance and that guidance is showing the majority of the rainfall on Sunday remaining near the coast onshore to roughly I-10. Looks like the greatest period for heavy rainfall continues to by Sunday night into Monday.

Rainfall Amounts:
Widespread rainfall amounts of 2-4 inches are likely south of I-10 with isolated higher totals easily to 6 inches or greater. Rainfall totals will reduce northward with totals likely less than an 1 inch across our northern counties. Deep tropical moisture will be in place Sunday-Tuesday and will support intense short duration rainfall rates of 2-3 inches per hour. Any training or slowing of banding features will quickly result in higher rainfall rates, street flooding, and rises on area creeks and bayous.

It should be noted that there will likely be a fairly sharp gradient in rainfall totals across the area with high pressure remaining in control just to our NE. Greatest totals will focus near Matagorda Bay with lesser totals toward Lake Livingston.

Hydro:
Grounds remain generally dry across the region and will be able to absorb 1-3 inches of rainfall before significant run-off begins. Intense hourly rainfall rates will generate run-off quickly even with dry grounds. While rises on area watersheds are certainly possible, at this time this does not appear to be a major flooding event. Main threat will be street flooding with the intense short duration rainfall rates. Additionally, away from any training, breaks between waves of rainfall should allow systems to drain and the ground to absorb the water.

As grounds saturated into Monday, run-off will be increasing and will need to monitor creeks and bayous closely for rises.

Marine:
Generally downhill across the coastal waters from this point onward as wave axis and deep moisture approaches and then moves inland. Winds will increase today out of the ESE/SE into the 20kt range with seas building 5-7 feet this afternoon and into the 9-11 foot range on Sunday into Monday. Numerous waves/squalls will be developing across the waters with gusty winds greater than 30-35kts.

Long fetch of ESE winds and long period swells will begin to increase the total water level along the coast to between 2-3 feet Sunday into Monday. This will likely produce some run-up on the Gulf facing beaches during this period. Conditions will be very slow to improve early next week with continued high seas and long fetch ESE/SE winds.

Forecasted Rainfall Totals (5-days):

Tidal Forecast for Galveston Pleasure Pier (MLLW):

[/i]

[brooksgarner]

I agree that the satellite presentation this morning is impressive and honestly a little bit eyebrow raising… I suspect if this convection persists through 2 PM Eastern time ( assuming it’s not purely nocturnal convection ), we will see at least a 40% hatch area in the NHC update. Of course, doing that would change a lot of things in their forecast including assigning it an invest ... so it would be a rather large step. This may be one of the systems that defies the models due to its chaotic beginnings. However, as long as you have outliers models like icon forecasting so much impact, they won’t ignore.

[srainhoutx]

After a close inspection of the various channels on GOES 16, this amazing tool in such high resolution provides a lot of details. Low/Mid and Upper level Water Vapor shows the trough to the West of the "blob" (highly technical meteorological term) as wxman57 would say moving into Mexico and deep tropical moisture being pulled generally WNW to NW. The NE Ridge is evident across East/NE Texas. There does appear to be some mid level 'spin' associated with the convective blob and we see feathering of the highest cirrus canopy increasing. As Brooks stated, should convection activity continue throughout the day, I see no way that the NHC cannot increase chances for TC Genesis somewhat. We will be monitoring all weekend and into next week.

[unome]

http://rammb-slider.cira.colostate.edu/ ... mmb-slider

http://www.ssd.noaa.gov/PS/TROP/TCFP/atlantic.html

[stormlover]

Nam is following icon footsteps

[unome]

wind toys

https://www.ventusky.com/
https://earth.nullschool.net/
https://www.windy.com/

[FreeportTX35]

So I'm confused I just washed Blake Matthews live on Facebook and he was saying that blob down there wasnt impressive he assured us of that....now we have Brookes saying things could get interesting.. so what do we believe?

[unome]

https://www.nhc.noaa.gov/marine/forecas ... ed_gom.php

Synopsis for the Gulf of Mexico
1036 AM EDT Sat Jun 16 2018

.SYNOPSIS...A strong surface trough extending from near 24N89W to the eastern Bay of Campeche will move WNW through early Sun night accompanied by numerous showers and thunderstorms that could produce rough seas. A tightening of the pres gradient between the trough and high pres that extends westward from the Atlantic will support fresh to strong SE winds over the west-central Gulf waters, increasing to strong to near gale force over the central Gulf this afternoon. These winds will spread westward through Tue while gradually diminishing with the trough shifting inland over Texas.

[unome]

new early AM blog post from Space City Weather

https://spacecityweather.com

[unome]

https://www.sailwx.info/wxobs/pressure.phtml

Barometric pressure reports in millibars within the last 12 hours.

[jasons2k]

As they say, timing is everything. 91L basically died off and we have this surprise wave taking its place, but a good 24-36 hours later (notice how the rain forecast quietly shifted by a day).

Over the years, I've seen a lot of hype around lead waves, only for it to be the sacrificial wave leaving a moist pocket in its wake. Then surprise surprise, wave #2 finds itself in a pocket of light shear over bath water. Suddenly, wave #1 is forgotten like it never existed...

Anyway, something to watch for sure. It has a window to 'gel' and it just might be in the process...it has the look. Will be telling what happens in a few hours when all the vortices move over water...