Area Forecast Discussion
Issued by NWS Huntsville, AL
Issued by NWS Huntsville, AL
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656 FXUS64 KHUN 191110 AFDHUN Area Forecast Discussion National Weather Service Huntsville AL 610 AM CDT Wed Jun 19 2024 ...New AVIATION... .NEAR TERM... (Today) Issued at 355 AM CDT Wed Jun 19 2024 An area of high altitude moisture from the tropics continued over the area, resulting in generally cloudy skies. A potential tropical system could form under these clouds over the southern Gulf of Mexico. Any effects from this system should remain well to our south. A strong upper level ridge over the Mid Atlantic had maximum heights at 500mb of near 597 decameters over WV/VA. This upper high will move a bit further to the north and amplify even more to the upper 590s to 600 decameters, and help produce unseasonably hot weather over much of the eastern and NE Lower-48. This ridge should weaken somewhat and build more to the south in the latter portion of the week. At the surface, a Bermuda high centered over the NW Atlantic basin was bringing an ESE flow over this region. 2 AM temperatures were mainly in the mid/upper 70s. Mostly cloudy high clouds should continue today. But a steady ESE flow of 5-10 mph overnight should increase into the 10-15 mph range later today. Somewhat lower heights due to the upper high drifting further to our NE should result in a "cooler" day for Juneteenth, with highs in the upper 80s to around 90. && .SHORT TERM... (Tonight through Friday night) Issued at 355 AM CDT Wed Jun 19 2024 Low temperatures tonight should cool to around 70 as the upper cloud deck slowly thins. With less cloud cover and the upper high heading southward, higher heights/thicknesses and a strong sun should return very warm to hot conditions on Thursday, highs rising into the lower 90s. Thu is also the first day of summer (which starts around 351 PM CDT). Similarly mild conditions Thu night with lows around 70. Friday, the first full day of summer will feel like summer, with highs warming into the low/mid 90s. Corresponding heat index readings should range in the 90s both Thu/Fri. And with high pressure controlling the weather, no precipitation is expected into early Saturday. && .LONG TERM... (Saturday through Tuesday) Issued at 355 AM CDT Wed Jun 19 2024 Guidance from the 0Z suite of global models suggests that a strong mid-level high will be centered across the TN Valley at the beginning of the extended forecast period. However, the subtropical ridge is predicted to retrograde with time this weekend (becoming centered across eastern NM/western TX by 0Z Monday) as a northern stream trough digs east-southeastward along the U.S-Canadian border and into the eastern Great Lakes. Although this evolution will result in a gradual increase in NW flow aloft for the TN Valley, highs will still manage to reach the m-u 90s in the valley on both Saturday and Sunday (u80s in elevated terrain), with heat indices in the 98-102F range as dewpoints creep back up into the u60s-l70s. Due to less of an impact from subsidence, a few afternoon/evening showers and thunderstorms will also return to the southeastern portion of the CWFA Saturday, with a slight increase in spatial coverage for all areas on Sunday. There is reasonably good agreement among the models that a weak cold front (attached to the northern stream trough) will drop southward through the region on Monday, and we have indicated our highest POPs for the extended period on this day. Frontal convection will likely end south of the TN River Monday evening, with the front expected to decelerate and become increasingly oriented in a NW-SE fashion to the west of the forecast area on Monday night/Tuesday. Although a slightly drier airmass may spread into the northeastern portion of the region, there is some uncertainty regarding precisely where the front will lie, and we have kept a low (~20% POP) intact for Tuesday. High temperatures will change little (if at all) in the wake of the front, but may be a couple of degrees cooler due to an increase in cloudiness both days. && .AVIATION... (12Z TAFS) Issued at 610 AM CDT Wed Jun 19 2024 VFR weather continues for the TAF. A flow of high altitude moisture from the tropics will produce broken to overcast conditions today. Otherwise high pressure off of the east coast will bring an ESE flow over the area. Winds around 5kt early should increase into the 10-15kt range from the mid morning through the afternoon, then become light from the ESE tonight. && .HUN WATCHES/WARNINGS/ADVISORIES... AL...None. TN...None. && $$ NEAR TERM...RSB SHORT TERM....RSB LONG TERM....70 AVIATION...RSB