261
FXUS64 KHUN 180558
AFDHUN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
1258 AM CDT SAT APR 18 2026
..NEW AVIATION
KEY MESSAGES
UPDATED AT 921 PM CDT FRI APR 17 2026
- THERE IS A HIGH (80-90%) CHANCE FOR SHOWERS AND THUNDERSTORMS
SATURDAY AFTERNOON AND EVENING. A FEW STORMS COULD PRODUCE
GUSTY WINDS AND SMALL HAIL.
- A COOL/DRY AIRMASS WILL OVERSPREAD THE REGION SUNDAY AND SUNDAY
NIGHT. THIS WILL BE FOLLOWED BY A DRY CONDITIONS AND A GRADUAL
WARMING TREND MONDAY-THURSDAY.
- A LOW CHANCE FOR SHOWERS AND A FEW THUNDERSTORMS WILL RETURN
FRIDAY AFTERNOON.
NEAR TERM
(THIS EVENING THROUGH SATURDAY)
ISSUED AT 921 PM CDT FRI APR 17 2026
AN INTENSIFYING MID/UPPER-LEVEL LOW WILL SHIFT EAST-NORTHEASTWARD
ACROSS MANITOBA/ONTARIO OVER THE COURSE OF THE NEAR TERM PERIOD,
WITH AN AMPLIFYING TROUGH EXTENDING SOUTH-SOUTHWESTWARD INTO THE
CENTRAL HIGH PLAINS. IN RESPONSE TO THIS, A DEEPENING AREA OF LOW
PRESSURE WILL TRACK NORTHEASTWARD FROM THE WESTERN GREAT LAKES
INTO SOUTHERN HUDSON BAY, WITH THE LOW'S TRAILING COLD FRONT
PREDICTED TO EXTEND FROM THE LOWER GREAT LAKES SOUTHWESTWARD INTO
THE EASTERN OZARK PLATEAU AND CENTRAL TX BY 12Z. ALTHOUGH DRY
CONDITIONS WILL PREVAIL ACROSS OUR REGION OVERNIGHT, AN INCREASE
IN HIGH-LEVEL CLOUDINESS IS EXPECTED PRIOR TO SUNRISE, AND THIS
ALONG WITH A LIGHT SSW WIND WILL YIELD OVERNIGHT LOWS IN THE
U50S-M60S. ALTHOUGH BRIEF DEVELOPMENT OF PATCHY FOG MAY OCCUR
AROUND 12Z IN WIND-SHELTERED LOCATIONS, CONDITIONS DO NOT APPEAR
FAVORABLE FOR SIGNIFICANT VISIBILITY REDUCTIONS AT THIS POINT.
THROUGHOUT THE LATE MORNING HOURS TOMORROW, AN OUTFLOW BOUNDARY
(ORIGINATING FROM WIDESPREAD CONVECTION ACROSS THE CENTRAL PLAINS)
IS EXPECTED TO SHIFT EASTWARD ACROSS WESTERN KY/TN AND NORTHERN
MS, ACCOMPANIED BY A THIN BAND OF SHOWERS AND PERHAPS A FEW
THUNDERSTORMS (WHICH COULD BEGIN TO IMPACT NORTHWEST AL BY
16-18Z). AS THIS FEATURE ADVANCES FURTHER SOUTHEASTWARD ACROSS OUR
REGION TOMORROW AFTERNOON (SEVERAL HOURS AHEAD OF THE ACTUAL COLD
FRONT), IT WILL ENCOUNTER A CAPPED BOUNDARY LAYER AND WEAK
CONVERGENCE MAY NOT BE ABLE TO GENERATE UPDRAFTS CAPABLE OF
PRODUCING LIGHTNING. HOWEVER, CAMS DO SUGGEST THAT MORE ROBUST
(BUT SLIGHTLY ELEVATED) CONVECTION MAY EVOLVE IN THE WAKE OF THE
OUTFLOW BOUNDARY BUT AHEAD OF THE COLD FRONT (WHICH SHOULD ENTER
NORTHWEST AL AROUND 22-23Z). WITH MID-LEVEL WSW FLOW INCREASING TO
45-55 KNOTS AND TEMPS IN THE L-M 80S SUPPORTING CAPE OF 300-500
J/KG, STEEP LOW-LEVEL LAPSE RATES MAY LEAD TO A FEW INSTANCES OF
STRONG WIND GUSTS (40-50 MPH) AND SMALL HAIL WITH THIS ACTIVITY,
WITH THE GENERAL TIMEFRAME FOR ANY POTENTIAL STRONG STORMS
EXPECTED TO BEGIN AROUND 20Z IN THE NORTHWEST AND END AROUND 2Z IN
THE SOUTHEAST.
SHORT TERM
(SATURDAY NIGHT THROUGH MONDAY NIGHT)
ISSUED AT 921 PM CDT FRI APR 17 2026
A RATHER STRONG COLD FRONT WILL CONTINUE TO SURGE SOUTHEASTWARD
THROUGH OUR FORECAST AREA TOMORROW EVENING, WITH THE RISK FOR
THUNDERSTORMS LIKELY TO END ACROSS OUR SOUTHEASTERN ZONES BY 2Z.
HOWEVER, WITH BROAD SCALE ASCENT EXPECTED TO STRENGTHEN WITH THE
APPROACH OF A MID-LEVEL TROUGH, CONDITIONS WILL REMAIN FAVORABLE
FOR LIGHT POSTFRONTAL RAIN (THAT SHOULD GRADUALLY END FROM NW-TO-
SE BEGINNING LATE SATURDAY EVENING). STORM TOTAL RAINFALL AMOUNTS
APPEAR AS IF THEY WILL RANGE FROM 0.75-1"(NW) TO 0.25-0.5" (SE),
ALTHOUGH IT IS CERTAINLY POSSIBLE THAT SOME LOCATIONS WILL RECEIVE
MORE (WHILE A FEW LOCATIONS MAY UNFORTUNATELY RECEIVE LESS).
STRONG NORTHERLY WINDS IN THE WAKE OF THE FRONT WILL QUICKLY
ADVECT A COOLER/DRIER, CONTINENTAL AIRMASS INTO THE REGION BY
SUNRISE ON SUNDAY, WITH LOWS EXPECTED TO BE IN THE M-U 40S.
DRY NORTHWEST FLOW ALOFT WILL EXIST ACROSS THE REGION FROM SUNDAY
THROUGH MONDAY NIGHT, BUT SHOULD WEAKEN BY THE END OF THE SHORT
TERM PERIOD AS A LOW AMPLITUDE RIDGE TRAVELS EASTWARD FROM THE
SOUTHERN ROCKIES INTO THE LOWER MS VALLEY. MODERATELY STRONG CAA
WILL CONTINUE THROUGHOUT THE DAY ON SUNDAY, YIELDING HIGHS RANGING
FROM THE LOWER 60S ATOP THE CUMBERLAND PLATEAU TO THE M-U 60S IN
THE VALLEY. AS SURFACE HIGH PRESSURE BUILDS EASTWARD INTO THE MID-
SOUTH REGION SUNDAY AFTERNOON, WINDS WILL DIMINISH, AND THIS
ALONG WITH MOSTLY CLEAR SKIES WILL SUPPORT COOL OVERNIGHT LOWS
MONDAY MORNING (L-M 40S). WINDS WILL REMAIN LIGHT/VARIABLE ON
MONDAY AND MONDAY NIGHT WITH HIGH PRESSURE CENTERED TO OUR
NORTHEAST, AND A GRADUAL WARMING TREND IS ANTICIPATED AS HIGHS
REBOUND INTO THE L-M 70S MONDAY.
LONG TERM
(TUESDAY THROUGH FRIDAY)
ISSUED AT 921 PM CDT FRI APR 17 2026
EXTENDED RANGE SOLUTIONS FROM THE GLOBAL MODELS SUGGEST THAT A
GENERAL ABSENCE OF SYNOPTIC SCALE FORCING FOR ASCENT WILL EXIST
FOR MUCH OF THE EXTENDED PERIOD, AS A LOW-AMPLITUDE SHORTWAVE
TROUGH PROGRESSING SOUTHEASTWARD FROM THE SOUTHERN PLAINS INTO THE
EASTERN GULF (TUESDAY-WEDNESDAY NIGHT) WILL BE FOLLOWED BY MID-
LEVEL HEIGHT RISES. THIS, ALONG WITH LINGERING INFLUENCES FROM A
WEAKENING DOME OF HIGH PRESSURE (CENTERED OFF THE SOUTHEASTERN
ATLANTIC COAST), WILL RESULT IN DRY WEATHER CONDITIONS FOR THE
MAJORITY OF THE EXTENDED PERIOD. THERE ARE SOME INDICATIONS THAT
SHOWERS AND A PERHAPS A FEW THUNDERSTORMS MAY RETURN TO WESTERN
PORTIONS OF THE FORECAST AREA FRIDAY AFTERNOON IN ADVANCE OF A
SURFACE LOW OVER THE NORTHERN PLAINS AND COLD FRONT DROPPING
SOUTHEASTWARD INTO THE MID-MS VALLEY. HOWEVER, THERE IS A LARGE
AMOUNT OF UNCERTAINTY REGARDING THIS SCENARIO, AND EVEN IF A FEW
STORMS MANAGE TO DEVELOP, BOTH SHEAR AND INSTABILITY WOULD FAVOR
WEAK/UNORGANIZED CONVECTION AT THIS TIME. TEMPERATURES WILL
CONTINUE TO INCREASE, WITH HIGHS RETURNING TO THE L-M 80S
(WEDNESDAY-FRIDAY), AND OVERNIGHT LOWS RISING INTO THE M-U 50S.
AVIATION
(06Z TAFS)
ISSUED AT 1236 AM CDT SAT APR 18 2026
VFR CONDITIONS ARE LIKELY TO PERSIST AT KHSV AND KMSL TAF SITES
THROUGH AT LEAST 18Z. HOWEVER, DETERIORATING CONDITIONS ARE
EXPECTED TO BEGIN BY ~22-00Z AS A CDFNT AND ASSOCIATED LINE OF
SHRA WITH ISOLD/SCTD EMBEDDED TSRA CROSSES INTO THE AREA.
PREVAILING MVFR CEILINGS/VIS ARE ANTICIPATED WITH THE LINE OF
SHRA, BUT EMBEDDED TSRA MAY BRING LOWER IFR VIS/CEILINGS (~30%
PROBABILITY). WINDS WILL VEER SWRLY TO NRLY WITH THE FRONTAL
PASSAGE, WITH GUSTS ~20KTS (POTENTIALLY HIGHER WITH ANY TSRA).
CONDITIONS EXPECTED TO IMPROVE TO VFR AT KMSL BY THE END OF THE
PERIOD ALTHOUGH -SHRA/RA MAY REMAIN, WHILE VFR EXPECTED AT KHSV
JUST AFTER TAF END TIME.
HUN WATCHES/WARNINGS/ADVISORIES
AL...NONE.
TN...NONE.
NEAR TERM...70
SHORT TERM....70
LONG TERM....70
AVIATION...KDW
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