Severe Potential March 30th 2012

March 30-31st 2012 Spring Storm

Low pressure located this evening over the Nebraska/ KS region with a frontal system extending east will move East NE before starting to move more eastwards..

This low pressure will be located over central Illinois by Friday afternoon . This low should move east from there into eastern Indiana by Friday evening and will begin to push a warm front towards the region.

This is what you call a SWFE ..or a South West Flow Event..warmer air will begin to penetrate into the upper levels..while at the surface some seasonable to slightly below seasonal air will be in place.

Due to the timing of this system in the over night period..we have included the potential for mainly higher elevations to receive a winter mix but for the most part we are expecting a cold rain across the region.

Generally at this time we think that snow accumulations would be less then an inch with surface temperatures in the coldest areas in the middle 30s overnight…

This low should slide south of PA..and off the east coast…

Rain should develop towards the midnight hour and last into early Saturday AM

Severe Outlook for 3/28/12

Alright for starters we have placed above the outlook for tomorrow. The current radar and the current surface map…

Re: Current radar you can see that there is little to no moisture return over the northern areas where SPC had issued the slight risk for today.  As of 7:25 PM not one storm report has come out via SPC..

Re: Current surface map shows a low pressure system across N Wisconsin. From there a warm front extends to the South South east and a cold front trails behind that..

Out ahead of this warm front is a cooler air mass but you can see the warm air that is surging NE with the warm front. We never like to depend on a warm front to bring us severe weather chances so it is no surprise that presently we are not seeing all that much happening.

If you look at the current radar again you will see that there is moisture return over the SW part of TX. This should continue to increase in this region.

The low over N Wisconsin should continue to evolve towards the east and then be in a location over Northern NY /Canadian border by Wednesday evening 8 PM.

What this will do is two fold:

1. It will allow warmer temperatures to make there way into the PA region with the advancing east of the warm front.

2. It will drag a cold front across the region. This cold front should spark off some showers and possibly some general thunderstorms across the PA region but over all the front is pretty much a dry front.. In other words not much moisture to work with. So that is the reason why Western PA and E PA into NJ is in just a low risk of thunderstorms. There will be a warm up which will be followed by a cool down and in this region that will continue to be the main weather story..

Now..the rest of the area will have a greater chance of severe weather with CAPE ranging from 500 to 3000. Lift Index of 0 to – 8.. Lapse rates are 6.5 + ..and shear 30-40 knots..

The greatest of the severe threat looks to reside around OK and KS region.

At this time we think the main threats will be gusty winds and hail but if there were to be any isolated tornados it would be across OK where EHI is greatest and would be in the evening as the southerly jet stream increases!

Severe Potential the 24th of March!

CAPE 500-1000, Lift Index 0 to -6 , Lapse rates 6.0-7.0..shear appears to be lacking in the northern areas in SW PA for example but around the vicinity of the low itself shear of 30-40 knots in place... The same upper level low that has been spinning its way from the south central states is now on the move to the north and the east. This low should slowly make its way east now and this low will once again be responsible for severe weather across the area along with heavy rains. Winds and hail (with the colder air aloft) should be the primary threats..However..can not rule out the chances of tornados..

Severe Potential Low ..Heavy Rain Potential 3/23-3/28 2012

It is not very difficult to pick out the upper level low in the south central USA. This upper level low has been responsible for severe weather that past couple days as it has slowly been moving its way towards the east.

This low pressure area will go south of the PA /MD border focusing its heaviest rains just north and along its track. To the north of the heavy rain map we have created will be lighter rains but these locations will be under an inch of rain..

Severe weather outlook.

SPC has a slight risk issued for tomorrow..We however are not seeing this happening. SREF is not very impressed with severe weather. Today 3/22/12 thus far severe weather has been on the quiet side..

CAPE is not all that impressive either with generally 1000 or below.

Lift Index is generally 0 to –4

Lapse rates are 5.5 to 8.0..the steeper lapse rates in the further north portion of the low risk highlighted area (in yellow)

Shear will generally be 35 knots +

So because of the shear and the lapse rates we have issued a low risk for areas that we think have the greatest potential of severe weather meaning winds and or hail..

We think the greatest threat from this system will be the heavy rains. While general thunderstorms are possible just about anywhere within the rain shield ..severe weather we do not expect to be a widespread problem.. Clouds and convective rains will keep the potential on the lower side..

March 19th Severe Weather Outlook

The yellow zone is the equivalent of a slight risk.

The Gray area represents a 5% risk area or low risk area.

Severe Parameters

CAPE 500-3000 depending on your location..

Lift Index is 0 to –8 depending on where you live in the zones.

Mid Level Lapse Rates 5.0 to 8.5

Shear is 35 knots +

Trigger is a low pressure which should be strengthening and moving to the NE towards the Dakotas late in the day with a cold front that trails to the south from the north..

Dry line will stretch from North to south ahead of the cold front.. Once again this dry line will be the focus of the severe weather but again there will also be a CAP in place.

This CAP should be overcome with the warmer surface temps which should help to moisten the lower levels of the atmosphere..

There will be the potential for tornado’s but again the main threats should be hail and damaging winds along with some very heavy rain across the zones..

Severe Outlook March 18th 2012

This is our day 2 outlook for Sunday...

Severe Parameters
CAPE looks to be 500-2500 depending where you are located
LI is 0 to - 8 again depending where you are located
Mid Level Lapse Rates 7.0-8.0 depending on location

At the surface low pressure will be moving across Wyoming with associated trough which should take a negative tilt. A cold front will be stretched from north to south..
Initially we think that the region will be relatively capped but storms should develop along the dry line which should be located N to south ..almost along the TX/NM border but slightly east of that border... Its near this dry line that should have the greatest risk of severe weather.
Initially as we stated we think that things will be kind of scattered and moisture return may be an issue as well...
Greatest threats appear to be Large Hail and Winds...

In the evening ..which is when the trough should begin to take on a more negative tilt ..it is at this time that coverage should become more wide spread. This whole system will advance slowly east wards so that monday ..the severe threat will shift further to the east...