Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion 
National Weather Service Midland/Odessa Texas
652 PM CDT Wed may 27 2015



Aviation...
00z taf issuance...
the main aviation concerns for the next 24 hours is thunderstorms and rain this
evening and low cigs early Thursday morning. Currently have gusty southeast
winds at all but peq where erratic thunderstorm winds prevail. Have
some severe convection affecting the region this evening and will
continue mention of thunderstorms and rain for the next couple of hours at peq and ink
then arrive at hob around 01z. May see convection hang around for a
while and will continue to monitor for any changes to current tafs.
Large hail is the main threat with these storms although heavy
rainfall will likely result in a brief period of low vis. Overnight,
gusts should subside however sustained speeds are expected to remain
somewhat elevated. Increasing moisture will result in low stratus
affecting all but maybe peq during the early morning hours Thursday.
Otherwise, cigs will lift and scatter by mid morning and VFR
conditions will prevail.

&&

Previous discussion... /issued 247 PM CDT Wed may 27 2015/

Discussion...

The dryline is along the terrain of the Davis and Guadalupe
Mountains this afternoon. An upper level trough is over the western
conus with the County Warning Area under west to southwest flow aloft. A surface
trough is developing across far West Texas and a shortwave trough is
expected to move over the area later this afternoon. Upper level
lift is expected to be rather impressive later today according to
the nam80 with 500 mb Omega values enhanced over The Trans Pecos and
a vorticity maximum over this same area. Mid-level lapse rates will
be good this afternoon and early evening with values of 8+ degrees
c/km for some places. Surface cape values according to the nam12
are very impressive this afternoon with many places having values of
4000+ j/kg. Bulk shear values of 35 - 40 kts on the nam12 in
addition to the previously mentioned conditions will be sufficient
for severe thunderstorms to develop beginning this afternoon. High
temperatures for today are expected to be similar to yesterday.

The storms that develop today are expected to continue into the
overnight period. Cape values will decrease throughout the night
but will still remain good, and upper lift will still be enhanced
over the area as shortwaves move overhead so severe storms will
remain possible through the night. Mid-level lapse rates will be 8+
degrees c/km across a large portion of the area by 12z Thursday
providing great instability. It is possible that an mesoscale convective system similar to
Monday morning could develop during the early to mid morning hours
on Thursday. Severe weather will likely develop/continue into
Thursday afternoon given good mid-level lapse rates, widespread cape
values of 4000+ j/kg, and sufficient bulk shear. Storm development
during the afternoon hours on Thursday will depend on whatever
develops during the early morning hours and the
boundaries/conditions left as a result of this convection. The 12z
run of the nam12 doesn't have any precipitation across the County Warning Area at
06z Friday, but both the GFS and European model (ecmwf) indicate very heavy precip
across the eastern half of the County Warning Area at this time. Might need a Flash
Flood Watch for this time period but do not have enough confidence
to issue one at this point.

Rain and storm chances will decrease by Friday afternoon but will
still be possible given that a dryline will be present. A cold
front associated with an upper trough moving over the upper Midwest
will push into the County Warning Area Saturday morning. Lift along this front will
once again increase precipitation chances across the area for
Saturday. Highs on Saturday will cool into the mid 70s to mid 80s
across the area as a result of this front and the associated
precipitation. Rain and storms will remain possible across the
higher terrain on Sunday afternoon as a result of the front.
Temperatures on Sunday are expected to remain cool as the surface
ridge will be across the area. Rain chances will still be present
but will significantly decrease Monday through Wednesday of next
week as an upper ridge builds over the region. Temperatures will
also increase to near normal values during this time.

&&

Maf watches/warnings/advisories...
nm...none.
Texas...none.

&&

$$

27

Follow US on facebook and twitter at:
http://facebook.Com/nwsmidland
http://twitter.Com/nwsmidland

Check US out on the internet at:
http://weather.Gov/Midland

National Weather Service Glossary of Abbreviations