559
FXUS64 KHUN 281720
AFDHUN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
1220 PM CDT WED MAY 28 2025
..NEW AVIATION
NEAR TERM
(REST OF TODAY AND TONIGHT)
ISSUED AT 1120 AM CDT WED MAY 28 2025
GENERALLY ZONAL TO SOUTHWEST FLOW WILL PERSIST ALOFT TODAY AND
TONIGHT. ADDITIONALLY, A SURFACE BOUNDARY HAS STALLED OVER THE
REGION AND LOOKS TO REMAIN IN PLACE BEFORE AN UPPER TROUGH PUSHES
THE FRONT SOUTHEAST LATER IN THE WEEK. THIS WILL KEEP GENERALLY
UNSETTLED AND MUGGY CONDITIONS IN THE FORECAST. FOR TODAY, THERE
ARE SCATTERED LIGHT SHOWERS MOVING ACROSS SOUTHERN MIDDLE
TENNESSEE AND NORTHERN ALABAMA AT PRESENT. LOW CHANCES (10-20%) OF
SHOWERS AND STORMS WILL THEN CONTINUE THROUGH THIS AFTERNOON, BUT
STRONG TO SEVERE STORMS NOT ANTICIPATED DUE TO LOWER INSTABILITY
AND SHEAR. HIGHS REMAIN ON TRACK TO TOP OUT IN THE UPPER 70S TO
LOWER 80S LATER THIS AFTERNOON.
LITTLE TO NO RAIN CHANCES ARE THEN FORECAST OVERNIGHT TONIGHT;
ALTHOUGH, SOME HI-RES GUIDANCE SUGGESTS THAT A FEW SHOWERS MAY
PUSH INTO THE REGION FROM THE SOUTH/SOUTHWEST FROM OUTFLOW
BOUNDARIES FROM EXPECTED STORMS TO OUR SOUTH OVER THE DEEP SOUTH.
ANOTHER CONCERN TONIGHT WILL BE LOW TO MEDIUM (20-40%) CHANCES OF
PATCHY TO AREAS OF FOG FOR ALL OF NORTH ALABAMA AND SOUTHERN
MIDDLE TENNESSEE. SOME OF THIS MAY BECOME DENSE IN A FEW
LOCATIONS, JUST LIKE LAST NIGHT. WE'LL MONITOR OBSERVATIONS THIS
EVENING AND OVERNIGHT IN CASE ANY DENSE FOG BECOMES WIDESPREAD
ENOUGH FOR A DENSE FOG ADVISORY. LASTLY, LOW TEMPERATURES ARE
EXPECTED TO MERELY DIP INTO THE LOWER TO MID 60S DUE TO ELEVATED
MOISTURE.
SHORT TERM
(THURSDAY THROUGH FRIDAY NIGHT)
ISSUED AT 1120 AM CDT WED MAY 28 2025
AN UPPER SHORTWAVE LOOKS TO TRAVERSE THE SOUTHEAST ON THURSDAY,
WITH A LARGER SHORTWAVE TROUGH SWINGING OVER THE REGION FOR LATE
WEEK. THE AFOREMENTIONED LINGERING SURFACE BOUNDARY OVER THE
REGION IS SET TO PUSH SOUTHEAST ON FRIDAY AS THE LARGER UPPER
TROUGH SWINGS OVER THE OHIO AND TENNESSEE VALLEYS. THUS, RAIN AND
STORM CHANCES CONTINUE THROUGH THE REMAINDER OF THE WORK WEEK.
MEDIUM TO HIGH CHANCES (35-60%) THURSDAY AFTERNOON BECOME HIGH
(65-80%) THURSDAY NIGHT, WITH RAIN/STORMS THEN PUSHING EAST FRIDAY
AFTERNOON.
THERE LOOKS TO BE POTENTIAL FOR A FEW STRONG TO SEVERE STORMS ON
THURSDAY AS WELL. MODEL GUIDANCE INDICATES A STRENGTHENING 30-35
KNOT LOW LEVEL JET MOVING INTO NORTHWEST ALABAMA AND PORTIONS OF
SOUTHERN MIDDLE TENNESSEE THURSDAY AFTERNOON INTO THURSDAY
EVENING. IN ADDITION, BULK SHEAR VALUES RANGE BETWEEN 30-40 KNOTS
WITH INSTABILITY BETWEEN 1000-1500 J/KG AND LOW LEVEL LAPSE RATES
BETWEEN 8.0-8.5 DEG C/KM. THIS IS ESPECIALLY TRUE FOR AREAS WEST
OF I-65 DURING THE AFTERNOON INTO THE EVENING. THIS IS COINCIDENT
WITH A MARGINAL RISK (LEVEL 1 OF 5) OF SEVERE WEATHER OUTLOOKED BY
THE STORM PREDICTION CENTER. HI-RES MODELS SHOW AN MCS
PROGRESSING INTO NORTHWEST ALABAMA DURING THIS TIME, BUT BREAKING
UP AND POSSIBLY WEAKENING AS IT DOES. MORE ISOLATED SHOWERS/STORMS
ARE ALSO SHOWN BEFORE THIS ACTIVITY EARLIER IN THE AFTERNOON.
WITH LIMITED SRH, THE MAIN THREATS WITH ANY STRONG TO POSSIBLY
SEVERE STORM THAT MAY DEVELOP THURSDAY AFTERNOON AND EVENING WILL
BE DAMAGING WINDS AND HAIL.
A BROKEN LINE OF SHOWERS AND STORMS WILL THEN DEVELOP LATER
THURSDAY NIGHT AHEAD OF THE COLD FRONT AND TRAVERSE THE LOCAL AREA
THROUGH LATE FRIDAY MORNING. A FEW STRONG STORMS THAT COULD
PRODUCE SOME GUSTY TO DAMAGING WINDS AND SMALL HAIL MAY OCCUR WITH
THIS MORNING ACTIVITY, ESPECIALLY WITH MODELS SUGGESTING AMPLE
BULK SHEAR AND POSSIBLY MODEST INSTABILITY (500-1000 J/KG)
LINGERING AHEAD OF THE FRONT. HOWEVER, CONFIDENCE IN THIS
OCCURRING IS LOW WITH THIS BEING DURING THE MORNING HOURS (VERSUS
PEAK HEATING IN THE AFTERNOON). FURTHERMORE, MODEL PWATS INCREASE
FROM 1.4-1.5 INCHES THURSDAY AFTERNOON TO 1.6-1.7 LATE THURSDAY
NIGHT INTO EARLY FRIDAY MORNING. THESE VALUES GENERALLY RANGE
BETWEEN THE 75TH AND 90TH PERCENTILES WHEN COMPARED WITH BMX
SOUNDING CLIMATOLOGY. THUS, THESE WILL BE EFFICIENT RAINFALL
PRODUCERS, AND, WITH THE RECENT RAINFALL WE'VE SEEN RECENTLY COULD
LEAD TO AT LEAST NUISANCE TO MINOR FLOODING CONCERNS IN THE
HEAVIER SHOWERS/STORMS.
SHOWERS MAY LINGER INTO THE AFTERNOON BEFORE DRYING OUT AS THE
FRONT PUSHES TO OUR SOUTHEAST LATE FRIDAY AFTERNOON INTO THE
EVENING. EXPECT HIGHS IN THE 70S THURSDAY AND FRIDAY, WITH LOWS
DECREASING FROM THE MID 60S THURSDAY NIGHT INTO THE MID TO UPPER
50S FRIDAY NIGHT DUE TO COLD FROPA.
LONG TERM
(SATURDAY THROUGH TUESDAY)
ISSUED AT 445 AM CDT WED MAY 28 2025
GLOBAL MODELS SUGGEST THAT DRY CONDITIONS WILL PERSIST ACROSS THE
TN VALLEY ON SATURDAY. HOWEVER, A BAND OF SHOWERS WILL LIKELY
EVOLVE TO OUR NORTH (FROM THE MID-MS VALLEY INTO THE SOUTHERN
APPALACHIANS) WITHIN A WEAK LOW-LEVEL CONFLUENCE ZONE PROVIDED BY
A REINFORCING/CONTINENTAL HIGH BUILDING SOUTHWARD FROM CANADA.
ALTHOUGH THIS ACTIVITY WILL BE LARGELY DRIVEN BY THE DIURNAL
WARMING CYCLE, AS THE HIGH MIGRATES FURTHER SOUTHEASTWARD INTO THE
CENTRAL APPALACHIANS LATE IN THE WEEKEND AND THE SURFACE
CONFLUENCE AXIS DRIFTS SOUTHWARD, THERE IS SOME CONCERN FOR
DEVELOPMENT OF SHOWERS AND THUNDERSTORMS IN OUR REGION ON SUNDAY.
HOWEVER, THIS WILL ULTIMATELY DEPEND ON WHERE THE SURFACE BOUNDARY
LIES (AND THIS COULD BE TO OUR NORTHEAST). IN ANY EVENT,
INSTABILITY WILL BE FAIRLY LOW (BUT SUFFICIENT FOR
LIGHTNING/THUNDER) AND NW WINDS ALOFT WILL ONLY BE IN THE 20-25
KNOT RANGE, SO ORGANIZED SEVERE CONVECTION IS NOT ANTICIPATED AT
THIS POINT. WE MAY ALSO BE IMPACTED TO SOME EXTENT (ON SUNDAY
NIGHT) BY THE REMNANTS OF AN MCS DROPPING SOUTH-SOUTHEASTWARD
ACROSS THE CENTRAL PLAINS ON SATURDAY, BUT THIS ASPECT OF THE
FORECAST IS QUITE UNCERTAIN AT THIS POINT. CONDITIONS WILL REMAIN
DRY EARLY NEXT WEEK AS THE SURFACE HIGH SHIFTS EASTWARD OFF THE
SOUTHERN MID-ATLANTIC COAST AND A MID-LEVEL RIDGE BUILDS ACROSS
THE SOUTHEASTERN CONUS.
AVIATION
(18Z TAFS)
ISSUED AT 1220 PM CDT WED MAY 28 2025
LITTLE TO NO RAIN IS FORECAST THROUGH TONIGHT, BUT CHANCES RETURN
BY THURSDAY AFTERNOON (MEDIUM, 30-40%). MVFR TO VFR CIGS WERE
OBSERVED ACROSS NORTHERN ALABAMA AND SOUTHERN MIDDLE TENNESSEE AT
ISSUANCE, WITH THE HSV TERMINAL AT VFR. MAINLY VFR CONDITIONS WILL
PREVAIL THROUGH THE REMAINDER OF THE AFTERNOON AND THROUGH THE
FIRST PART OF THIS EVENING; HOWEVER, LOWERING CIGS AND ESPECIALLY
VIS DOWN TO IFR ARE FORECAST LATER TONIGHT DUE TO PATCHY TO AREAS
OF FOG. SOME OF THIS FOG MAY BECOME LOCALLY DENSE. OBSERVATIONS
WILL BE MONITORED IN CASE LOWER VIS BEYOND 2SM IS NEEDED AT THE
TAF SITES LATER TONIGHT. ANY FOG SHOULD DISSIPATE THROUGH MID-
MORNING THURSDAY, BUT MVFR CIGS WILL LIKELY HANG ON THROUGH LATE
MORNING. LASTLY, WESTERLY WINDS AROUND 5 KNOTS WILL BECOME CALM
THIS EVENING, WITH LIGHT AND VARIABLE WINDS EXPECTED THURSDAY
MORNING.
HUN WATCHES/WARNINGS/ADVISORIES
AL...NONE.
TN...NONE.
NEAR TERM...26
SHORT TERM....26
LONG TERM....70/DD
AVIATION...26
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