Cap is dominating, SFC based storms unlikely before dark

A strong inversion exists on the 21Z MPX sounding with -274 J/kg of Mixed Layer CINH (convective inhibition) present. Surface based storms will likely not fire until near or after dark if at all. I am glad I didn't make the trip as this was one of my biggest concerns.

The latest MD issued by the SPC states the same thing: ....POTENTIAL FOR SURFACE BASED STORMS FARTHER SOUTH APPEARS LIMITED...BUT THESE AREAS WILL CONTINUE TO BE MONITORED.

Tornadoes in ND, Severe Weather likely again Tomorrow

Multiple tornado reports are coming in from North Dakota this evening. A line of isolated supercells erupted this afternoon ahead of a cold front in central ND and spread east into a primed environment for tornadoes. Here's a picture of the report locations for today.

Severe weather is likely again tomorrow, Monday August 27th, across ND,SD,MN, IA, and NE as the cold front continues its southward march. A strong cap may limit coverage but the forcing along the cold front coupled with the timing of the upper air disturbance may be enough to break through the inversion before nightfall. A surface low is forecast to move from central SD northeastward through Minnesota possibly backing surface winds and enhancing hodographs. The LLJ is forecast to be quite strong, 40-50kts, just after 00z making for impressive low-level shear values. Unfortunately I can't chase tomorrow due to school, the tough semester, but I'll keep an eye on it and I wouldn't be surprised to see a tornado or two reported tomorrow.

Gorilla Hail in South Dakota

This picture was taken in Dante South Dakota on the 21st of August after a classic supercell ripped through the region. Official reports of 4.25" diameter hail were recorded with "unofficial" hailstones reportedly in the 6-8" diameter range.

New pic from Hurricane Dean

http://www.capturethestorm.com/

Picture of Hurricane Dean taken by shuttle Endeavor near peak intensity in the Caribbean Sea.
http://upload.wikimedia.org/wikipedia/commons/9/90/HurricaneDean.jpg

Severe storms along cold front rest of this week.

http://www.capturethestorm.com/

A cold front dragging through the central US will present a focus for severe weather opportunities the rest of this week as it drags slowly south. Fairly zonal, mid level flow of 30 - 50 kts atop the frontal location coupled a decent LLJ the next couple of days could set the stage for numerous hail and wind report along with some isolated tornadoes wherever storms can stay discrete and not get undercut by the front.
Threat locations:
Tuesday 21st - Nebraska, southeast South Dakota, northern Kansas, Iowa
Wednesday 22nd - much of Iowa and Nebraska, eastern Colorado, northern Kansas
Thursday 23rd - Mainly Kansas and eastern Colorado

Severe Weather Possible this Afternoon

A remnant surface trough / dryline will interact with a nearly stationary surface boundary located over extreme eastern Nebraska and western Iowa. 40-50kts of deep layer shear exists which is ample for supercells along with isolated tornadoes possible given the low level directional shear in place.

EHI values, which is measured by the amount of CAPE and storm relative helicity (in this case the lowest 1km), are above 5 for eastern Nebraska. In general, 0-1km EHI's above 2 can support a decent tornado threat.

A weather watch, possibly a tornado watch, may be needed later this afternoon for the affected areas.

Tropical Depression Erin restrengthens over Oklahoma

The remnants of TD Erin has intensified overnight bringing massive flooding, multiple high wind reports, and a couple of tornadoes. HPC is now issuing advisories on the event. http://www.hpc.ncep.noaa.gov/discussions/tcpat5.html

Here are some of the rainfall totals for the past 24 hours:

Over 9" in 24 hrs at Fort Cobb, over 5" at Norman. Like I said, there is widespread flooding and river are beginning to overflow their banks.

A Break from the Heat

Some tropical air mass type thunderstorms have brought some much appreciated rain and cooler temperatures to Oklahoma today. The storms are associated with the remnants of Tropical depression Erin which is still spinning in northwest Texas and moving northeastward. Here are a few pics form Norman.

DEAN's forecast track shifted slightly north; may effect Texas

NHC "cone of uncertainty" has shifted a bit further north and the average path would now take Dean over the northern tip of the Yucatan. Of course the less time over the Peninsula would mean Dean would likely stay strong as it emerges back into the Gulf. Here's a look at the track from this morning's update.

The consensus among some of the tropical models has been a bit further north as well; except for GFS and CMC which have been staying to the south. Here is a look at this morning's GFDL run which could spell big trouble if it verified.

TS Erin: Heavy Rain and possible Tornadoes for the Texas Coast

Tropical Storm warnings are in effect for the Texas coast as TS Erin is set to make landfall sometime Thursday near Corpus Christi, TX. The threat of localized flooding is present with QPF's around 7'' near the Corpus / Port Aransas region.

Brief, weak tornadoes are possible beginning tonight and going into the day on Thursday from and area near Galveston south along the coast to about Corpus Christi. The moist, unstable tropical air mass will be in place along with favorable wind profiles in this region to support isolated tropical type funnels, waterspouts, and weak tornadoes. SPC has just raised their tornado probabilities in the latest outlook.

Soon to Be TS Dean, Trouble in Gulf as well

The tropical disturbance in the Atlantic will soon become TS Dean but we have a while to watch it being so far away.

Of more importance now is the possible development of Tropical Depression in the Gulf. Invest 91L is just north of the Yucatan and some models forecast it to hit the Texas coast as a TS or a weak hurricane.

More in depth updates tonight....

Invest 90L

From the National Hurricane Center:

A VIGOROUS TROPICAL WAVE IS LOCATED OVER THE FAR EASTERN ATLANTIC OCEAN ABOUT 300 MILES SOUTH-SOUTHEAST OF THE SOUTHERNMOST CAPE VERDE ISLANDS. CONDITIONS APPEAR FAVORABLE FOR GRADUAL DEVELOPMENT OF THIS SYSTEM...AND A TROPICAL DEPRESSION COULD FORM DURING THE NEXT DAY OR TWO AS IT MOVES WESTWARD AT 15 TO 20 MPH.

Another area to monitor is the Caribbean where widespread convection is found this morning. Shear over the area isn't the most favorable but if there is enough low level convergence, a low level circulation could form.

Hurricane Season is here

Models are beginning to show increased tropical cyclone activity in the Atlantic Basin over the next few weeks. Not to say one model will verify over another, but the consensus of the upcoming pattern is quite similar. Above, NAM shows a system located near the Yucitan peninsula. Below, the CMC has had a similar feature for a couple of runs now.

The GFS on the other hand, does not pick up on this potential system but has been consistent with something developing off the African coast sometime next week.

A look at the Atlantic Basin now shows some convection in the Carribean and some convergence along about 10N.

I wouldn't give up on this season at all. Things may just be getting started and I would almost bet on seeing another named system within the next two weeks.

Possible Chase Friday 10th

A series of shortwaves have been making there way through the northern plains with a stronger one forecast to move thorugh the Dakotas Friday afternoon/evening. The differences in the timing among the models is the only thing that concerns me. Both the GFS and NAM show good instability and deep layer shear for supercells with the NAM forecasting very high, low-level shear values enhancing the overall tornado threat if it verifies. I might be making this trip so stay tuned. Early target would be somewhere near Euraka - Aberdeen, SD.

Updates To Site

I've finished updating quite a few things including my individual storm chase reports.

Still left to work on:
-Hurricane Page
-Links Page
-Font problems
-This Blog

www.capturethestorm.com

New Site

Hello, hope you enjoying the new site, www.capturethestorm.com, feel free to visit often and check back here as I will be updating this blog on info about upcoming chases and weather news.