Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

fxus64 khun 222049 

Area forecast discussion
National Weather Service Huntsville Alabama
249 PM CST Wed Nov 22 2017

Near term...(tonight)
issued at 230 PM CST Wed Nov 22 2017

Latest water vapor imagery shows a fairly amplified upper ridge over
much of the western conus, with a trough over the eastern Continental U.S..
this places the Tennessee Valley within a broad area of northwest flow
aloft. At the surface, high pressure continues to build
southeastward into the region, with northerly flow across the area.
Under this dome of high pressure, clear skies are expected to
persist across the Tennessee Valley through the remainder of the day and
into the overnight hours. Winds may stay elevated between 5 and 10
mph through the early evening hours, before diminishing after
midnight. This may prevent initial radiational cooling after sunset,
however once winds become calm, temperatures will likely drop fairly
rapidly. Thus, expecting a fairly cold night, with temps falling
into the upper 20s by daybreak on Thursday.

Short term...(thursday through friday)
issued at 230 PM CST Wed Nov 22 2017

Thanksgiving day should be fairly pleasant, though on the cooler
side, as high pressure persists across the region. The upper level
pattern looks to change very little through the day on Thursday and
into Friday, with the Tennessee Valley remaining between an amplified upper
ridge to the west and a trough over the northeast Continental U.S.. winds will
generally remain from the north on Thursday and then begin to shift
more southerly on Friday as high pressure builds along the Gulf
Coast. Highs on Thursday will be a couple degrees warmer than those
observed today, with highs in the mid to upper 50s and overnight
lows in the lower 30s. The return southerly flow on Friday will
advect slightly warmer and more moist air, with temps rising into
the lower 60s.

Long term...(friday night through tuesday)
issued at 235 PM CST Wed Nov 22 2017

By Friday night, a broad, low amplitude trough will be present
across the eastern conus, but a short wave trough and associated
reinforcing shot of colder Continental air will move ewrd across the
Great Lakes and Ohio/Tennessee Valley regions. Ahead of the surface cold front,
southerly flow will largely consist of a mix of maritime and
residual Continental air. With a lack of sufficient moisture
advection, this is still expected to be a dry frontal passage. The
center of high pressure associated with the cooler airmass will move
to our north on Sunday, keeping dry cold air advection ongoing across
our area, but temperatures will likely climb into the mid 50s at
most locations under mostly sunny sky conditions. A temperature
rebound will begin on Monday as the high shifts to our east and low-
level southerly flow returns once again to the region. Temperatures
may reach the low or mid 60s at most locations on Monday and Tuesday.
The next frontal boundary appears poised to cross the region perhaps
on Wednesday, with precipitation chances increasing during the day.
This next front may contain stronger mid/upper dynamics and low/mid-
level moisture advection than the front on Friday night/Saturday


Aviation...(for the 18z tafs through 18z Thursday afternoon)
issued at 1120 am CST Wed Nov 22 2017

VFR conditions will prevail at the kmsl and khsv terminals through
the next 24 hours as high pressure settles in across the region.
Northerly winds may be gust up to 15 kts at times through 22z and
then diminish this evening.


Hun watches/warnings/advisories...


Near term...73
short term...73
long term...kdw

National Weather Service Glossary of Abbreviations