Friday, May 20, 2011

Planned Updates for this summer to the blog

-Addition of hurricane models
-More comprehensive coverage of hurricanes
-Comprehensive coverage of severe weather

May 20: Tornado Warning (Strong Indication of Tornado)- Nesbitt, TX

SEVERE WEATHER STATEMENT


NATIONAL WEATHER SERVICE SHREVEPORT LA

646 PM CDT FRI MAY 20 2011



TXC203-315-210030-

/O.CON.KSHV.TO.W.0072.000000T0000Z-110521T0030Z/

HARRISON TX-MARION TX-

646 PM CDT FRI MAY 20 2011



...A TORNADO WARNING REMAINS IN EFFECT UNTIL 730 PM CDT FOR MARION

AND HARRISON COUNTIES...



AT 645 PM CDT...DOPPLER RADAR CONTINUED TO SHOW STRONG INDICATION

OF A TORNADO JUST NORTHWEST OF NESBITT...MOVING NORTHEAST AT

35 MPH. IF YOU LIVE IN THE NESBITT OR WOODLAWN AREAS...TAKE

COVER IMMEDIATELY.



PRECAUTIONARY/PREPAREDNESS ACTIONS...



A TORNADO WARNING MEANS THAT STRONG ROTATION HAS BEEN DETECTED IN THE

STORM. A TORNADO MAY ALREADY BE ON THE GROUND...OR IS EXPECTED TO

DEVELOP SHORTLY. IF YOU ARE IN THE PATH OF THIS DANGEROUS STORM...

MOVE INDOORS AND TO THE LOWEST LEVEL OF THE BUILDING. STAY AWAY FROM

WINDOWS. IF DRIVING...DO NOT SEEK SHELTER UNDER A HIGHWAY OVERPASS.



May 20: Severe Thunderstorm Watch #313

Storms currently firing in the west portion of this watch area are likely to become linear as they intensify after hitting the warm and moist sector.
There is the possibility for strong, organized storm fragments, such as supercells.

May 20: Tornado Watch

Thunderstorms should continue to intensify as the storms enter a moist and unstable atmosphere. To the southwest is a thunderstorm watch.
We expect these storms to intensify, possibly into a linear structure, then move North northeast.
There is enhanced concern of low level rotation and an increase of tornadoes.

May 20: Local Area Emergency- East Prairie County, Montana

Local Area Emergency




--------------------------------------------------------------------------------



MTC079-202200-



URGENT - IMMEDIATE BROADCAST REQUESTED

LOCAL AREA EMERGENCY

MONTANA EMERGENCY MANAGEMENT AGENCY GLASGOW MONTANA

RELAYED BY NATIONAL WEATHER SERVICE GLASGOW MT

944 AM MDT FRI MAY 20 2011



...LOCAL AREA EMERGENCY...



THE FOLLOWING MESSAGE IS TRANSMITTED AT THE REQUEST OF THE

PRAIRIE COUNTY DISASTER AND EMERGENCY SERVICES.



IN EASTERN PRAIRIE COUNTY...CABIN CREEK BRIDGE ON CABIN CREEK ROAD

HAS BEEN WASHED OUT BETWEEN THE THONEY AND HOUSEHOLDER RESIDENCES.

THERE IS NO THROUGH TRAFFIC ON THE CABIN CREEK ROAD IN THIS AREA.



El Nino/La Nina Projections (May 20)

The IRI has updated their ensembles containing what climate models believe will happen in regards to El Nino or La Nina.
Below is the Ensemble.
The average of all models actually went down by .1 degree Celsius from the April forecast to the May forecast.
As we can see, there are outliers, but the general consensus is for a neutral winter, as the average is at or below .5 degrees Celsius.
The CPC also makes an ENSO (name for El nino/La Nina) projection.
Below are the ensembles from the latest 10 days.
This ensemble also has a neutral winter in mind for the United States. However, the latest 10 forecast members to get in on this ensemble would have the most accurate information. That said, it appears the outliers on the ensemble are actually more into a La Nina/neutral winter phase instead of an El Nino/neutral winter phase.
Is this a sign of things to come?
I do have more images from the IRI to answer this question.
I took a look at the individual models that make up the ensembles and found 3 that compared good in past forecasts to what played out.
Those 3 models are the
ECMWF model
JMA Model
ESSIC Model
The ECMWF model above didn't have a clear bias, which was good. Even better, the forecasts had been nearly always on track with what happened, especially during the last several months.
The ESSIC model above does seem to have somewhat of a La Nina bias. While it's been right for some time, the El Nino wasn't handled correctly during 2009. But, since it does get it's forecasts right at some points, I had to include it.
Finally, the JMA model does seem to have a slight El Nino bias, but it shows only to some extent. The forecasts were nearly right on track with what happened, just a little warmer during the El Nino.

In conclusion, I am going towards a neutral 2011 as we move into the rest of the year.
Another projection will be made next month.

May 20: Place to Be- Chattanooga, Tennessee

Today's Place to be is Chatanooga, Tennessee.

Chattanooga
HIGH- 86
Weather- Mostly Sunny
Wind- Calm becoming West 5mph

May 20 Severe Weather

Storms will continue to be on the increase early today in Western Texas and Western Oklahoma. GOES Satellite and radar data is already showing that this has occurred. Convective action will intensify into the day and continue eastward, feeding off the warmth and humidity. While deep layer shearing and lapse rates decrease out east, there is still a marginal severe hail and modest severe wind threat.

However, given that this convective activity has already begun in a widespread fashion, there is definitely concern regarding the degree of instability in the wake of the morning storms. However, a narrow corridor from West Central Texas through West Central Oklahoma and Kansas will be in place where some instability could build up again. Should that happen, that area would be the main focus for more convective activity. Residual outflow boundaries and the Pacific Front forcing these storms along may support new rounds of thunderstorms. With stronger flow aloft (40-45 kt), there is an environment supportive for supercells and bowing segments. However, hodographs (weather instrument) limit this threat to some extent.

Today's Hail threat

Today's tornado threat

Today's wind threat