942
FXUS64 KHUN 210417
AFDHUN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
1017 PM CST FRI FEB 20 2026
..NEW NEAR TERM, SHORT TERM, LONG TERM
KEY MESSAGES
UPDATED AT 1017 PM CST FRI FEB 20 2026
- A HIGH COVERAGE OF SHOWERS IS EXPECTED OVERNIGHT, WITH A LOW
CHANCE OF THUNDERSTORMS. LIGHTNING, BRIEF HEAVY RAINFALL AND
PERHAPS SOME SMALL HAIL WILL BE THE MAIN IMPACTS FROM THE
THUNDERSTORMS.
- ANOTHER ROUND OF LIGHT RAIN IS EXPECTED LATE SATURDAY AFTERNOON
AND SATURDAY EVENING, FOLLOWED BY A COLD/DRY AIR MASS THAT WILL
LINGER THROUGH MONDAY NIGHT.
- A WARMING TREND WILL BEGIN TUESDAY, WITH ANOTHER CHANCE FOR
SHOWERS AND THUNDERSTORMS ON THURSDAY.
NEAR TERM
(THIS EVENING THROUGH SATURDAY)
ISSUED AT 1017 PM CST FRI FEB 20 2026
IN THE MID/UPPER-LEVELS, WEST-SOUTHWESTERLY FLOW OF 75-85 KNOTS
WILL PERSIST ACROSS THE TN VALLEY THROUGH THE DURATION OF THE NEAR
TERM PERIOD AS OUR REGION WILL REMAIN ALONG THE NORTHWESTERN RIM
OF A SUBTROPICAL RIDGE CENTERED EAST OF THE BAHAMAS. WITHIN THIS
REGIME, A PAIR OF SHORTWAVE IMPULSES (INITIALLY ACROSS THE FOUR
CORNERS AND SOUTHERN ROCKIES) WILL PHASE AS THEY EMERGE ACROSS THE
CENTRAL PLAINS OVERNIGHT, WITH AT LEAST PARTIAL PHASING WITH A
SEPARATE, LOWER-LATITUDE DISTURBANCE (CURRENTLY ACROSS THE
SOUTHWESTERN DESERTS) POSSIBLE AS BOTH FEATURES ADVANCE EAST-
NORTHEASTWARD ON SATURDAY. IN RESPONSE TO THIS, WINDS AT THE
850-MB LEVEL HAVE BACKED TO SSW AND WILL INCREASE INTO THE 20-30
KNOT RANGE OVERNIGHT, RESULTING IN SUFFICIENT LIFT WITHIN THE
PRESENCE OF A MOIST PROFILE TO SUPPORT WEAK CONVECTION ACROSS A
BROAD REGION FROM SOUTHERN AR INTO SOUTHEASTERN TN/NORTHERN GA.
WITH UPDRAFTS ROOTED ABOVE A STABLE BOUNDARY LAYER (TO THE NORTH
OF A STALLED FRONT EXTENDING FROM THE SABINE VALLEY INTO NORTHERN
SC) AND ONLY SMALL AMOUNTS OF ELEVATED CAPE (UP TO 200 J/KG)
OCCASIONAL LIGHTNING AND BRIEF MODERATE-HEAVY RAINFALL WILL BE THE
MOST SIGNIFICANT IMPACTS. HOWEVER, IF A CELL IS ABLE TO SUSTAIN
AN APPRECIABLE (40-50 DBZ) CORE UP TO 16-18 KFT, THEN SOME SMALL
HAIL MAY OCCUR, AS WELL.
HIGH-RESOULTION MODEL CONSENSUS SUGGESTS THAT THIS PRECIPITATION
REGIME WILL END FROM NW-TO-SE IN THE 10-14Z TIMEFRAME, AS A WEAK
FRONTAL WAVE BEGINS TO SHIFT EAST-NORTHEASTWARD ACROSS SOUTHERN
PARTS OF AL/GA. HOWEVER, LOW STRATUS CLOUDS WILL EXIST FOR MUCH OF
THE DAY, AND WITH NNW WINDS AND LOW-LEVEL COLD ADVECTION EXPECTED
TO STRENGTHEN DURING THE AFTERNOON, WE EXPECT HIGHS TO RANGE FROM
THE L60S/NW TO U60S/SE. AS MID-LEVEL ASCENT BEGINS TO INCREASE
TOMORROW AFTERNOON AHEAD OF THE SERIES OF PHASING WAVES TO OUR
WEST, AN AXIS OF LIGHT RAIN WILL BEGIN TO EVOLVE FROM CENTRAL KY
SOUTHWESTWARD INTO WESTERN TN/NORTHERN MS, AND WITH THE LEADING
EDGE OF THIS REGIME EXPECTED TO ENTER THE WESTERN PORTION OF OUR
CWFA BY 22-0Z, WE HAVE INDICATED AN INCREASE IN POPS IN THIS
REGION TO 10-15%.
SHORT TERM
(SATURDAY NIGHT THROUGH MONDAY NIGHT)
ISSUED AT 1017 PM CST FRI FEB 20 2026
DEEP-LAYER LIFT WILL CONTINUE TO STRENGTHEN ACROSS THE FORECAST
AREA ON SATURDAY NIGHT/EARLY SUNDAY MORNING, AS A SHORTWAVE TROUGH
SHIFTS EAST-NORTHEASTWARD WITHIN THE FLOW AROUND A DEVELOPING
COLD CORE VORTEX ACROSS THE LOWER GREAT LAKES. THIS WILL OCCUR AS
THE LEADING EDGE OF A COLD, ARCTIC AIRMASS (ORIGINATING FROM A
1055-1060 MB ANTICYCLONE ACROSS THE NORTHWEST TERRITORIES) BEGINS
TO ENTER THE REGION, WITH LIGHT STRATIFORM RAIN PREDICTED TO
EXPAND IN COVERAGE DURING THE EVENING HOURS FROM THE CUMBERLAND
PLATEAU/SOUTHERN APPALACHIANS SOUTHWESTWARD INTO SOUTHERN PORTIONS
OF THE TN VALLEY. PRECIPITATION IS EXPECTED TO EXIT THE EASTERN
PART OF OUR FORECAST AREA BY 6Z (IF NOT SOONER), AND ALTHOUGH THIS
WILL OCCUR SHORTLY BEFORE PROFILES WOULD SUPPORT A TRANSITION TO
A RAIN/SNOW MIX, A FEW FLURRIES MAY OCCUR EARLY SUNDAY MORNING
UNTIL THE POSTFRONTAL STRATUS LAYER ERODES SHORTLY BEFORE SUNRISE.
STRONG NNW WINDS WILL DRIVE OVERNIGHT LOW TEMPERATURES INTO THE
U20S-L30S, WITH ATTENDANT WIND CHILLS AROUND 10 DEGREES COLDER.
NORTH-NORTHWEST WINDS WILL REMAIN ELEVATED FOR AN EXTENDED PERIOD
FROM SUNDAY THROUGH LATE MONDAY AFTERNOON AS THE CENTER OF THE
PARENT ARCTIC HIGH SHIFTS EAST-SOUTHEASTWARD INTO WESTERN ONTARIO
WHILE A SURFACE LOW (INITIALLY NEAR THE COAST OF NC) UNDERGOES
BOMBOGENESIS AS IT LIFTS NORTHEASTWARD OFF THE MID-ATLANTIC COAST.
ALTHOUGH A COUPLE OF SMALL, BUT WELL-DEFINED MID-LEVEL WAVES WILL
DIG SOUTHEASTWARD AROUND AN INTENSIFYING COLD CORE VORTEX TO OUR
NORTHEAST, THE LOCAL AIRMASS WILL REMAIN TOO DRY TO SUPPORT
PRECIPITATION. HOWEVER, STEEP LAPSE RATES RELATED TO THE COLD
POCKETS ALOFT WILL LEAD TO OCCASIONAL STRATOCUMULUS CLOUDS. HIGHS
WILL STRUGGLE TO REACH THE L-M 40S ON SUNDAY AND MAY NOT SURPASS
THE 35-40F RANGE ON MONDAY (PERHAPS REMAINING NEAR FREEZING ATOP
THE CUMBERLAND PLATEAU). OVERNIGHT LOWS WILL BE IN THE L-M 20S
SUNDAY NIGHT (MORNING WIND CHILLS IN THE 5-15F RANGE), WITH CALM
WINDS AND CLEAR SKIES MONDAY NIGHT RESULTING IN LOWS IN THE UPPER
TEENS-LOWER 20S.
LONG TERM
(TUESDAY THROUGH FRIDAY)
ISSUED AT 1017 PM CST FRI FEB 20 2026
LATEST EXTENDED RANGE GUIDANCE SUGGESTS THAT BROAD CYCLONIC FLOW
ALOFT WILL REMAIN INTACT ACROSS CENTRAL/EASTERN NORTH AMERICA
THROUGHOUT THE LONG TERM PERIOD, WITH THE ONLY FEATURE OF INTEREST
BEING A SHORTWAVE TROUGH THAT WILL TRAVEL FROM THE PACIFIC
NORTHWEST INTO THE CANADIAN MARITIME PROVINCES BETWEEN TUESDAY AND
FRIDAY. AS SURFACE HIGH PRESSURE MIGRATES SOUTHEASTWARD AND AWAY
FROM THE REGION ON TUESDAY, LIGHT SSW RETURN FLOW WILL INITIATE
THE BEGINNING OF A WARMING TREND THAT WILL CONTINUE UNTIL THE
PASSAGE OF ANOTHER COLD FRONT (RELATED TO THE AFOREMENTIONED
SHORTWAVE TROUGH) AT SOME POINT DURING THE DAY ON THURSDAY.
ALTHOUGH LOW-LEVEL MOISTURE RETURN WILL INITIALLY BE SLOW TO OCCUR
ACROSS THE SOUTHEASTERN CONUS, A PLUME OF DEWPOINTS IN THE MID
50S MAY RETURN NORTHEASTWARD AHEAD OF THE COLD FRONT, SUPPORTING
DEVELOPMENT OF A FRONTAL SQUALL LINE. INSTABILITY WILL LIKELY BE
LIMITED BY PRECEDING CLOUDS AND POOR LAPSE RATES ALOFT, BUT TRENDS
IN THE QUALITY OF BOUNDARY LAYER MOISTURE WILL NEED TO BE CLOSELY
MONITORED OVER THE COMING DAYS AS BOTH DEEP-LAYER AND LOW- LEVEL
SHEAR WOULD SUPPORT ORGANIZED/SEVERE CONVECTION. A SLIGHTLY
COOLER/DRIER AIRMASS WILL RETURN TO THE REGION IN THE WAKE OF THE
FRONT TO END THE WORK WEEK.
AVIATION
(00Z TAFS)
ISSUED AT 646 PM CST FRI FEB 20 2026
CONDITIONS WILL GRADUALLY DETERIORATE AT THE HSV/MSL TERMINALS
OVER THE COURSE OF THE NIGHT, AS ELEVATED ATMOSPHERIC LIFT
STRENGTHENS TO THE NORTH OF A STALLED FRONTAL BOUNDARY LYING
ACROSS SOUTHERN PORTIONS OF THE GULF COAST STATES. BASED ON
CURRENT RADAR/SATELLITE DATA AND SFC OBS, WE HAVE INDICATED VFR
CIGS AT FL100 AND LGT SHRA AT THE BEGINNING OF THE PERIOD, WITH
CLOUD BASES EXPECTED TO DESCEND FURTHER TO 5KFT BY 2Z CONCURRENT
WITH AN INCREASE IN THE COVERAGE/INTENSITY OF SHRA. A FEW EMBEDDED
TSRA MAY ALSO OCCUR (PARTICULARLY BTWN 3-7Z), WHICH MAY WARRANT
ISSUANCE OF AWWS FOR OCCASIONAL LIGHTNING AND PERHAPS SOME SMALL
HAIL. AS THE AXIS OF HEAVIER SHRA/TSRA BEGIN TO SPREAD EASTWARD
AND AWAY FROM THE TERMINALS EARLY SAT MORNING, CIGS WILL FALL TO
MVFR LEVELS, WITH A FEW LINGERING LGT SHRA AND MINOR VSBY
REDUCTIONS POSSIBLE THRU 12Z. PRESENT INDICATIONS ARE THAT A BKN-
OVC DECK OF LOW/MVFR STRATUS WILL PERSIST FOR THE REMAINDER OF THE
TAF PERIOD, WITH A SHARP WIND SHIFT TO NNW EXPECTED BY 19-20Z.
HUN WATCHES/WARNINGS/ADVISORIES
AL...NONE.
TN...NONE.
NEAR TERM...70/DD
SHORT TERM...70/DD
LONG TERM...70/DD
AVIATION...70/DD
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