A joint service of the UK Ag Weather Center and the National Weather Service.
A quasi-stationary front was located near TOI and EUF early this
evening. The front really made no progress northward as a weak
wave moved along it this afternoon. This front will continue to
meander across the far southern reaches of the area tonight and
Monday. Quite an airmass difference across the front with highs in
the 40s north and 70s southeast. South to west winds will
continue in the lower levels just above the front. This moisture
will ride over a relatively cool airmass and low clouds and fog
are expected. Some of the fog will become dense at times, with
visibilities 1/2 mile or less. Will hold off on an advisory at
this time and try to narrow down an area better. An advisory may
become necessary and will monitor observations closely for a later
update. Rain will remain possible close to the front south with
Previous short-term discussion:
Light rain with a few pockets of moderate rain continues to
overspread the area as a weak surface boundary sets up across the
southern half of the state. The rain should gradually end from
west to east through the late afternoon and evening hours as the
boundary weakens and stalls to the south. It is likely that the
steady light rain will become more showery and drizzle through the
overnight as low clouds and some patchy dense fog develops.
Expect this pattern to continue until the next potent shortwave
ejects from the west early Wednesday.
Monday through Sunday:
Southwesterly anti-cyclonic flow will be in place on Monday around
deep layer ridging centered between Florida and Cuba. A split flow
pattern will remain in place with a southern cutoff low over the
Desert Southwest and northern stream troughing over Canada. A
precipitation-reinforced quasi-stationary front will extend from
the Louisiana Gulf Coast northeastward toward southeast Alabama.
The eastern portion of this boundary may drift southward during
the morning following passage of a weak meso-low. Precipitation
forecast remains challenging due to weak/broad forcing associated
with weak waves in the southwest flow, and how quickly a residual
cold pool/area of dry air erodes in the wake of today's activity.
Showers and thunderstorms will develop late tonight/early tomorrow
morning along the frontal boundary in the vicinity of the
Louisiana Gulf Coast in a broad area of upper-level lift
associated with the right entrance region of an upper-level jet
streak and lift to the east-northeast. Generally favor a non-GFS
solution with a further south position of the front due to outflow
from today's activity and highest rain chances closer to the Gulf
Coast with some activity bleeding over into our southern
counties. A separate area of mid-level frontogenesis and moisture
will located further north closer to the I-20 corridor, which
could allow for some rain to fall there as well if low-level dry
air can be overcome. So, kept a mention of scattered showers in as
far north as Birmingham with lower confidence. Weak elevated
instability will be in place across the southern counties which
could allow for a rumble or two of thunder, but any surface-based
instability and potential for any stronger storms should remain
south of the forecast area. Also not expecting any heavy rain
during this time. Temperatures will hinge on precipitation and
lingering cool air. Will indicate highs in the upper 50s to low
60s north and mid to upper 60s south (low 70s possible far
southeast), but confidence is low as some high-res guidance keeps
temperatures across the north in the low 50s.
Some showers may linger near the I-20 corridor through the
evening. Focus for showers shifts to the northwest after midnight
as low-level isentropic lift strengthens ahead of the cutoff low
ejecting out of West Texas, and as the front lifts northward as a
warm front. This also results in a non-diurnal temperature trend
with temperatures steady/rising slightly after midnight.
Models indicate a west to east band of moderate to heavy rainfall
developing along and north of the warm front as unseasonably high
PWATs intersect the boundary. This area of heavy rain has been
trending northward, so the main threat of flooding seems to be
shifting north of the forecast area, but will continue to
monitor. The strong shortwave will move through the area late
Tuesday night and Wednesday morning while getting squeezed between
the subtropical ridge and troughing over the northeastern CONUS.
Models seem to be converging on the forecast area being in the
warm sector of a surface low moving across northern Mississippi
and middle Tennessee with low to mid 60s dewpoints and a few
hundred J/kg of CAPE ahead of a cold front/dry-line like feature.
There are still some key differences regarding the strength of the
low and associated backing of the low-level winds, and how soon
the low-level winds will veer out relative to the instability
arriving. If trends continue, a threat for isolated tornadoes late
Tuesday night and Wednesday morning could be added to the HWO in
later issuances given favorable wind profiles for mini-supercells.
Thursday through Sunday:
One dry day is expected on Thursday between systems with the only
forecast challenge being a possible wedge briefly trying to build
in. Focus then shifts to the next southern-stream trough ejecting
out of the western CONUS, and eventually phasing with a deep
northern stream trough engulfing almost the entire CONUS. Another
cold front looks to move into the area during the Friday/Friday
night timeframe. Any threat for severe weather will depend on the
degree of moisture return in the wake of Wednesday's system.
Models and ensembles have had many varying solutions for this
weekend regarding whether the front moves through, stalls, or
retreats off to the northwest, and whether the expected outbreak
of arctic air catches up to precipitation along the front. It's
certainly too early to use any deterministic model runs at this
point. General consensus continues to support only mentioning
liquid precipitation through the current forecast period at this
Alabama Forecast Discussion (NWS)
National Ag. Weather Outlook, International Ag. Weather Summary
Current Surface Map,
[2nd Source TWC]
Click here for UKAWC Point Agricultural, Lawn & Garden Forecast/Outlook in case of corrupt tables.
Regional Hourly Observations For SHELBY County
600 PM CST SUN DEC 17 2017
CITY SKY/WX TMP DP RH WIND PRES REMARKS
BIRMINGHAM CLOUDY 46 45 96 NE3 30.16S
6HR MIN TEMP: 42; 6HR MAX TEMP: 47; 6HR PCP: 0.11;
MONTGOMERY CLOUDY 51 48 89 N3 30.11S FOG
6HR MIN TEMP: 49; 6HR MAX TEMP: 51; 6HR PCP: 0.11;
SHELBY CO ARPT CLOUDY 47 47 100 CALM 30.14S FOG
6HR MIN TEMP: 44; 6HR MAX TEMP: 48; 6HR PCP: 0.06;
MAXWELL AFB CLOUDY 50 50 100 NE3 30.10F
6HR MIN TEMP: 48; 6HR MAX TEMP: 50; 6HR PCP: 0.11;
GREENVILLE CLOUDY 63 60 90 S7 30.12R FOG
6HR MIN TEMP: 57; 6HR MAX TEMP: 63; 6HR PCP: 0.30;
SELMA CLOUDY 50 48 93 N5 30.12R
PRATTVILLE CLOUDY 48 48 100 CALM 30.11F
6HR MIN TEMP: 46; 6HR MAX TEMP: 48; 6HR PCP: 0.10;
BESSEMER CLOUDY 46 46 100 E3 30.14S FOG
6HR MIN TEMP: 42; 6HR MAX TEMP: 47; 6HR PCP: 0.03;
TALLADEGA DRIZZLE 45 45 99 CALM 30.17R
6HR MIN TEMP: 43; 6HR MAX TEMP: 47; 6HR PCP: 0.06;
PELL CITY CLOUDY 45 45 100 CALM 30.17R FOG
MARION CLOUDY 47 47 100 NE3 30.11S FOG
6HR MIN TEMP: 44; 6HR MAX TEMP: 47; 6HR PCP: 0.02;
SYLACAUGA CLOUDY 48 48 100 CALM 30.16R
6HR MIN TEMP: 46; 6HR MAX TEMP: 49; 6HR PCP: 0.16;
Current Agricultural Weather Conditions in Alabama
Based on observations at 600pm CST, Sunday December 17, 2017
Across Alabama...temperatures are near 47 degrees north, near 46 degrees central, and near 67 degrees south. Current sky conditions are cloudy north, cloudy central, and cloudy south. In the north, relative humidity is near 93%, and the dew point is near 45 degrees. In the central part of the state, relative humidity is near 96%, and the dew point is near 45 degrees. In the south, relative humidity is near 97%, and the dew point is near 66 degrees. Winds are from the southeast at 7 mph north, where conditions are favorable for spraying. Winds are from the northeast at 3 mph central, where conditions are favorable for spraying. Winds are from the southeast at 3 mph south, where conditions are favorable for spraying. The livestock cold stress index is in the no stress category north, no stress category central, and no stress category south. Based on current available observations, the highest temperature is 67 degrees at Mobile, Evergreen, and Dothan. The lowest temperature is 42 degrees at Gadsden.
Current NOWCAST not available:
Nowcasts are not issued routinely during fair weather. Only when
precipitation or other significant weather is occuring in this county will these
forecasts be issued. Currently, there is no short term forecast in effect.
U.S. Radar Map,
All NWS Radars (In near-real time),
Current Livestock Heat Stress Index (LSI),
Current Wind Chill Map
Hazardous Weather Outlook For SHELBY County, AL
937 AM CST Sun Dec 17 2017
DAY ONE Outlook through Tonight.
Patchy dense fog or low clouds will be possible across much of
Central Alabama through the overnight hours. Visibilities may drop
to or below 1 mile at times.
DAYS TWO THROUGH SEVEN Monday through Saturday.
Patchy dense fog or low clouds may continue through 9 am Monday
morning. Visibilities may drop to or below 1 mile for much of Central
SPOTTER INFORMATION STATEMENT
Activation of storm spotters and emergency management is not
expected at this time.
NWS Severe Weather Map , Convective Outlook
7-Day Forecast For SHELBY County, Alabama
702 PM CST Sun Dec 17 2017
Cloudy. Patchy dense fog in the evening. Areas of
dense fog after midnight. Chance of rain in the evening.
Occasional drizzle through the night. Slight chance of rain after
midnight. Near steady temperature in the upper 40s. Northeast
winds around 5 mph in the evening then becoming light. Chance of
rain 30 percent.
MONDAY Cloudy. Patchy fog in the morning. Scattered rain
showers in the afternoon. Highs in the lower 60s. Light winds.
Chance of rain 40 percent.
MONDAY NIGHT Cloudy with a 20 percent chance of rain showers.
Near steady temperature in the lower 50s. Light winds.
TUESDAY Rain showers likely and slight chance of
thunderstorms. Highs in the mid 60s. Southwest winds around
5 mph. Chance of rain 70 percent.
TUESDAY NIGHT Rain showers and chance of thunderstorms. Near
steady temperature around 60. South winds around 5 mph. Chance of
rain 80 percent.
WEDNESDAY Cloudy. Showers and chance of thunderstorms in the
morning, then chance of showers in the afternoon. Highs in the
upper 60s. Chance of rain 80 percent.
WEDNESDAY NIGHT Cooler. Mostly cloudy. Lows in the upper 40s.
THURSDAY Partly cloudy. Highs in the mid 60s.
THURSDAY NIGHT Mostly cloudy. A 30 percent chance of rain
showers after midnight. Lows around 50.
FRIDAY Cloudy with a 50 percent chance of rain showers. Highs
in the mid 60s.
FRIDAY NIGHT Rain showers likely and slight chance of
thunderstorms. Lows in the upper 40s. Chance of rain 70 percent.
SATURDAY Cloudy with a 40 percent chance of rain showers.
Highs in the mid 50s.
SATURDAY NIGHT Mostly cloudy with a 30 percent chance of rain.
Lows in the lower 40s.
SUNDAY Mostly cloudy with a 40 percent chance of rain. Highs
in the mid 50s.
12-48 Hr Surface Forecast Maps,
TWC 4-Panel Surface Forecast,
Day 1 Precip,
Day 2 Precip,
Days 1-5 Precip,
Severe Weather Pot.-Day 1,
Medium & Long Range Outlook For Alabama
6 TO 10 DAY 8 TO 14 DAY 30 DAY 90 DAY
DEC 23-27 DEC 25-DEC 31 DEC DEC-FEB
----------- ----------- -------- ---------
Temperature: Normal Below Above Above
Precipitation: Above Normal Below Below
.... Medium and long range outlooks provided by NCEP/K. Thomas Priddy
5 Day Rainfall Forecast,
6 to 10 Day ,
8 to 14 Day ,
Sunday December 17, 2017 the 351th Day of Year
Distance 0.999725 AU
Rise 07:47 EST Set 17:43 EST
Transit Meridian 12:44 EST
Civil Twilight Begins 07:20 EST Ends 18:09 EST
Calculations made for central point in the state.
Time in ET -- and will vary due to location and
elevation -- Priddy
Historical Weather And Climate Facts For Today
HISTORIC WEATHER EVENTS
A three week blockade of snow began at Portland OR. A record December total
of 34 inches was received. (David Ludlum)
A severe icestorm struck central Illinois. It coated the ground with nearly
two inches of glaze at Springfield. The storm caused 21 million dollars
damage along with much hardship. Ice was on the trees until the 4th of
January, and electricity was not restored until January 10th. (David
An icestorm in western New York State resulted in much damage and hardship.
A Buffalo report stated, "one was kept awake by the breaking limbs, which
snapped off with a report much louder than a rifle shot." (17th-18th) (The
A storm in the southwestern U.S. brought heavy rain and heavy snow to parts
of California, Nevada, Arizona, Utah and New Mexico. Charleston NV was
blanketed with 12 inches of snow. Lake Havasu City AZ was drenched with
2.26 inches of rain. (Storm Data) (The National Weather Summary)
Squalls brought locally heavy snow to the southeastern shores of Lake
Michigan. Totals in Michigan ranged up to 14 inches at Harvey. Totals in
Ohio ranged up to 16 inches at Chardon. (The National Weather Summary)
Twenty-one cities from Kentucky to Pennsylvania reported record low
temperatures for the date, including Columbus OH with a reading of 12
degrees below zero. Heavy snow continued in the Colorado Rockies. Vail
received 65 inches of snow between the 14th and the 18th of December.
Steamboat Springs was buried under 74 inches, and reported a total of 108
inches of snow between the 10th and the 18th of the month. (The National
Weather Summary) (Storm Data)
Ag Weather Center, Department of Biosystems & Agricultural Engineering, University of Kentucky