Area Forecast Discussion
Issued by NWS Jackson, MS
Issued by NWS Jackson, MS
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341 FXUS64 KJAN 220301 AFDJAN Area Forecast Discussion National Weather Service Jackson MS 1001 PM CDT Sat Sep 21 2024 ...New MESOSCALE UPDATE... .MESOSCALE UPDATE... Issued at 1001 PM CDT Sat Sep 21 2024 Not much to talk about in the evening update. Weather conditions will remain quiet for the next several hours thanks to the sfc high pressure remaining centered over the Southern Appalachians and southeastern CONUS. HREF guidance is hinting at some patchy fog development mainly for areas south of I-20 starting a little after midnight. Sky conditions will be generally clear across central MS allowing for radiational cooling to occur our forecast area. Because of this, overnight lows will drop into the 70s with areas east of I- 55 dipping into the upper 60s. Updates are out. /CR/ && .DISCUSSION... Issued at 221 PM CDT Sat Sep 21 2024 Through Monday: Upper-level ridging will prevail over Northern Mexico and the Gulf Coast region as surface high pressure remains centered over the Southern Appalachians and southeastern CONUS. The pattern should keep our forecast area on the dry side of any disturbances passing to the north. Tuesday through Saturday: By Tuesday, the synoptic pattern will become much more complex. The ridge is expected to nudge eastward toward the southeastern CONUS with a positively-tilted trough axis deepening across the Plains states in its wake. This pattern change will at least allow for some increase in POPs Tuesday especially for our northwestern and western zones Tuesday as a cold front dips in and another shortwave ripples past in the flow aloft. Showers and possibly a few thunderstorms could develop heading into the daytime. What transpires Wednesday into the end of the week is a bit trickier to nail down. As the upper-level ridge gets locked near Florida, model guidance is picking up on the likelihood that the trough cuts off an upper-level low pressure system around the High Plains to mid- Mississippi River Valley region while the remaining northern stream energy continues eastward. At the same time, the energy and moisture associated with a Central American Gyre will be pivoting northward from the western Caribbean toward the Gulf of Mexico. Whether any closed tighter circulation can develop from this gyre remains a question, but the National Hurricane Center`s latest assessment of the situation places a 60% (Medium) chance for development of a Tropical Depression in the next 7 day time frame. This essentially covers the potential time frame of concern for the Gulf Coast region, as the latest suite of model guidance show the envelope of moisture and energy arriving toward the Gulf Coast in a Thursday to Saturday time frame. The exact way the upper trough, ridge, and gyre interact will ultimately determine when and where the impacts of heavy rain and/or winds are felt in the Gulf region. But at this point it remains a period of concern as portions of the region have experienced heavy rain associated with Francine, and areas of higher soil moisture as seen on MRMS, etc. could increase the potential for flooding if and when heavy rain develops. Individual model runs will remain highly variable due to the uncertain nature of these synoptic features. For now, please remain aware of developments in the forecast, especially if traveling around the Gulf Coast region through next weekend. /NF/ && .AVIATION... (00Z TAFS) Issued at 646 PM CDT Sat Sep 21 2024 Quiet & dry TAF period expected the next 24 hours. Some fair weather cumulus around the 6-8kft range are possible again into Sunday, with VFR flight categories. Patchy fog/BR can`t be ruled out in spots around daybreak, but confidence remains too low for any mention in the 00Z TAF cycle. Winds will be near calm tonight & light west-southwesterly into Sunday aftn, generally less than 10mph. /DC/ && .PRELIMINARY POINT TEMPS/POPS... Jackson 71 93 71 92 / 0 0 0 0 Meridian 70 94 70 93 / 0 0 0 0 Vicksburg 71 94 71 92 / 0 0 0 0 Hattiesburg 71 94 71 94 / 0 0 0 0 Natchez 70 93 70 91 / 0 0 0 0 Greenville 71 93 70 90 / 0 0 0 0 Greenwood 72 94 71 92 / 0 0 0 0 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...None. LA...None. AR...None. && $$ NF/DC