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Area forecast discussion
National Weather Service Birmingham Alabama
644 PM CDT Sat Sep 21 2019

Update...
for 00z aviation.

&&

Short term...
/updated at 0137 PM CDT Sat Sep 21 2019/
through tonight.

Southeast low level flow has brought an increase in moisture below
850mb across central Alabama. Fair weather cumulus has developed
during the heating of the day. The afternoon cumulus will slowly
erode this evening with clear skies by 9 or 10 PM. Lows tonight
will be slightly warmer than this morning's lows, with readings
across east Alabama in the upper 50s, and lower to middle 60s
elsewhere.

58/rose

Long term...
/updated at 0150 PM CDT Sat Sep 21 2019/
Sunday and Monday.

The deep-layer anticyclone remains overhead Sunday as subsidence
and a dry airmass prevents any rainfall. Highs will remain above
average heading into next week with most locations, outside of
eastern and portions of northern Alabama, reaching 90 degrees on
Sunday. On Monday, the ridge flattens along the Gulf Coast as the
base of an upper-level trough and associated cold front moves
southeastward across the Tennessee Valley. The cold front is
expected to reach northwestern Alabama by late Monday afternoon
with a thin axis of low to mid-level moisture present ahead of the
boundary. Weak lift is anticipated with this boundary as the main
trough, and thus synoptic-scale forcing, remains north of the
forecast area with the ridge centered to our southwest. Therefore,
only isolated to scattered showers are expected late Monday
afternoon in our far northwestern counties before activity
decreases heading into Monday evening. Cape values across the
northwest will be low for this time of the year due to low mid-
level lapse rates and surface temperatures in the northwest only
reaching the upper 80s. Therefore, there is only a slight chance
for thunder during the afternoon with mostly rain showers expected
with any activity. Low-level winds will become southerly to
southwesterly ahead of the boundary on Monday, allowing
temperatures to rise a couple of degrees higher than Sunday.

86

/updated at 0307 am CDT Sat Sep 21 2019/
Tuesday through Friday.

Quasi-zonal flow will temporarily set up across the area
Tuesday/Wednesday as a deepening trough over central Canada and
the north-central Continental U.S. Causes the core of the ridge to
temporarily be suppressed over the Gulf. This will allow the front
to continue to sink southward before stalling somewhere across
the area on Tuesday and then lifting northeastward on Wednesday.
The front and associated moisture axis could serve as a trigger
for showers/storms to develop Tuesday and Wednesday afternoons,
but at this time warm/dry mid-level air is expected to keep
coverage isolated. Models/ensembles continue to indicate an
amplified pattern setting up Thursday through next weekend, with a
deep trough over the western Continental U.S. Downstream of a blocking ridge
over the North Pacific, and a seasonably anomalous 595-596
decameter ridge setting up over the southeastern Continental U.S.. this ridge
combined with dry soils will result the potential for record
highs towards the end of the forecast period, with CPC indicating
high probabilities of above average temperatures and below normal
precipitation.

32/Davis



&&

Aviation...
00z taf discussion.

High pressure centered off the Carolina coast has promoted
generally southeasterly, light winds this evening though should
die down by ~02z. Any remaining scattered cumulus, particularly
near bhm & mgm per satellite, should diminish as well. Overnight
conditions expected to continue with VFR with a repeat of
afternoon VFR tomorrow. Winds generally southeast to S at ~4-7 kts with
cumulus re-developing by late morning and into the afternoon.
Happy flying.

40/sizemore

&&

Fire weather...

Dry and warm conditions continue through the weekend. The next
chance of rain comes Monday, but with only isolated to scattered
coverage across northwestern areas. Afternoon relative humidity
values are expected to remain above 30 percent each afternoon
through the weekend. Kbdi values will remain elevated as drought
conditions persist.

&&

Preliminary point temps/pops...
Gadsden 60 90 60 92 66 / 0 0 0 10 10
Anniston 61 90 63 92 67 / 0 0 0 0 10
Birmingham 65 90 66 93 69 / 0 0 0 10 10
Tuscaloosa 65 90 66 92 70 / 0 0 0 10 10
Calera 62 90 64 93 68 / 0 0 0 0 10
Auburn 62 87 65 90 68 / 0 0 0 0 0
Montgomery 64 91 63 94 68 / 0 0 0 0 0
Troy 62 90 63 93 66 / 0 0 0 0 0

&&

Bmx watches/warnings/advisories/...
none.

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