Area forecast discussion
National Weather Service Mobile Alabama
512 am CDT Sat may 25 2013
Short term...(today through monday)...for today through tonight...
upper level ridging will build from the western Gulf of Mexico
through Alabama/Mississippi today. Dry weather will continue across
our forecast area underneath this feature. Mostly sunny skies are
expected with only occasional high level cloud cover moving over the
region. Otherwise...a ridge of surface high pressure will extend from
the Great Lakes region to the southeastern U.S. Today with a light
northeasterly flow early this morning becoming more easterly to
southeasterly by afternoon. Expect highs to range from the middle 80s to
around 90 degrees again across most locations. Mostly clear and dry
conditions continue tonight with lows in the middle to upper 50s across
the interior...and in the lower to middle 60s near the coast. /21
This afternoon's wet microburst risk is low.
Sunday through Monday...two upper troughs...one each over the NE and
northwest Continental U.S....shift east...shifting the upper ridge over the plains to
over the miss River Valley. A shortwave over the Southern Plains
shifts east with...to over the northern Gulf Coast. The surface
ridge over the eastern Continental U.S. Takes a southeast path...to just off the East
Coast. Even with an upper shortwave over the area...guidance is slow
enough to move moisture back over the forecast area...along with a cap to limit
significant precipitation formation. NAM is slightly wetter...advertising a
slight chance of rain showers over the marine area. Have went with the
majority of guidance and kept the forecast area generally rain free. For
temperatures...around seasonal during the day...with overnight lows a bit
below due to the drier than seasonal airmass over the area.
Long term...(monday night on)...for Monday night through
Tuesday...the eastward shift in the upper features continue...with
the NE-eastern trough moving well off the East Coast...and the upper
ridge shifting over the Continental U.S....east of the miss river. The surface
ridge over the East Coast builds west over the northern Gulf of mex.
Moisture levels are on the increase with the low level flow becoming
a more organized southeasterly. With the forecast area coming under stronger
high pressure...temperatures above seasonal return.
Tuesday night through Wednesday...the western Continental U.S. Trough takes a
negative trough...pushing the upper ridge to over the East Coast.
Rain showers/thunderstorms and rain make a return back into the forecast...especially over
eastern sections of the forecast area...with the moderate onshore flow over the
northern Gulf Coast continues...and a shortwave swings around the
base of the western upper trough...swiping the lower miss River
Valley. A slight chance at best is expected...though. With precipitation
chances on the increase...temperatures cool a bit from the previous day over
western sections of the forecast area...but remain well above seasonal over
eastern sections.
Wednesday night through Thursday...the western upper trough organizes
a bit. A shortwave moves northeast over the eastern Gulf Coast from
south of the Caribbean. The GFS maintains a slightly warmer/wetter
solution than the European model (ecmwf)....but the difference is small. Have went
close to guidance for the forecast...with guidance in general
agreement.
Thursday night through Saturday...the medium range guidance begins to
diverge significantly. The western US trough organizes into an upper
low and swings east. The GFS is advertising a fast...more North
Passage than the European model (ecmwf). The slower European model (ecmwf) organized the upper system
more as it moves east. Both are advertising upper energy diving south
over the western Continental U.S....to varying extents. Over the southeastern
Continental U.S. Is where the patter really begins to diverge. The European model (ecmwf) takes
the shortwave over the eastern Gulf of mex and takes it
north...forming a surface low along the Florida Atlantic coast and taking
it north along the coast. The GFS meanders it slowly western over the
Gulf of mex...organizing it very little. For temperatures...both the European model (ecmwf)
and GFS are in pretty good agreement. For probability of precipitation...the European model (ecmwf) maintains
a drier solution over the forecast area than the GFS due tot the shortwave being
more distant from the forecast area. For the forecast...have generally went with
the GFS...with the GFS ensembles in pretty good agreement with the op
GFS.
&&
Aviation...[12z terminal forecast discussion]...VFR to prevail
through the period with few-scattered mainly high level cloud cover.
Northeast to east winds 5-10 knots this morning will become
southeasterly around 10 knots this afternoon. /21
&&
Marine...high pressure will continue to build into the southeastern
u... this feature ridging over the northern Gulf of Mexico
through tonight. Moderate northeasterly to easterly flow between
15-20 knots will continue over much of the marine area this
morning...before becoming southeasterly and decreasing this
afternoon and tonight. High pressure will continue to extend from
the western Atlantic through the northern Gulf late this weekend
through the middle of next week. Light to moderate east to southeast
flow will persist along with this pattern. /21
&&
Fire weather...northeast flow in the mixing layer has brought in
drier air over the forecast area...with afternoon relative humidity values dropping into the
middle 20 percent range. With erc values over Okaloosa County...Florida
rising above the magic 37 mark...will be issuing a red flag for
Okaloosa today. Escambia and Santa Rosa values remain well below
criteria levels for a Florida red flag.
Into the coming week...surface high pressure shifts over the eastern
Seaboard...then builds west north of the northern Gulf Coast through
the first part of the week. Winds in the mixing layer become
southeasterly in the process...with moisture levels on the increase.
Next best chance for rain appears to be Wednesday over western
sections of the forecast area. A slight chance...though.
&&
Preliminary point temps/pops...
Mobile 86 61 86 64 86 / 00 00 05 05 05
Pensacola 87 66 86 67 85 / 00 00 05 05 05
Destin 84 67 83 68 82 / 00 00 05 05 05
Evergreen 86 54 89 59 88 / 00 00 05 05 05
Waynesboro 86 56 87 58 86 / 00 00 05 05 05
Camden 86 53 88 59 86 / 00 00 05 05 05
Crestview 89 54 89 58 90 / 00 00 05 05 05
&&
Mob watches/warnings/advisories...
Alabama...none.
Florida...red flag warning from 11 am Saturday to 6 PM Saturday for the
following zones: coastal Okaloosa...inland Okaloosa...
MS...none.
GM...none.
&&
$$
21/16
