Area Forecast Discussion
Issued by NWS Columbia, SC
Issued by NWS Columbia, SC
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908 FXUS62 KCAE 251612 AFDCAE Area Forecast Discussion National Weather Service Columbia SC 1212 PM EDT Sat May 25 2024 .SYNOPSIS... A frontal boundary is expected to stall near the forecast area resulting in chances for showers and thunderstorms through the weekend. Another, more organized system is expected to cross the eastern US Monday and Tuesday with additional chances for thunderstorms. Drier weather is expected to return Wednesday. && .NEAR TERM /THROUGH TONIGHT/... Key points: MCS moving down into the CSRA between 1-5pm with straight line wind damage possible. Pulse severe potential across the Midlands and Pee Dee later this afternoon and evening. A weak MCS is moving across GA late this morning as a series of weak shortwaves aloft continue to push through the area. The MCS and associated convective line has generally remained sub-severe this morning thanks to some noticeable ML CIN and relatively low ML CAPE across northern GA. The environment will improve has the MCS progresses eastward thanks to strong heating across the CSRA and Midlands this morning with temps already into the mid-upper 80`s as of noon; surface CAPE has quickly jumped above 2000 j/kg for most of our area, with ML CAPE lagging slightly as the BL mixes out. Shear remains fairly weak across the board as the synoptic flow aloft is weak, but there is enough shear to support loose organization and a straight line wind threat. All the HREF and HRRR guidance has been quite terrible with handling this MCS since it has pushed into eastern TN and northern GA so their depiction of what will happen seems to be very suspect. So given the current behavior and environment, the MCS should slide southeastward, likely moving through the CSRA with strong- severe thunderstorms possible between 1pm-5pm. Outside of the MCS, scattered-isolated strong-severe thunderstorms are possible throughout the afternoon and into the evening but coverage should be somewhat limited compared to Friday with any pulse convection as the MCS should rack over the instability for a good chunk of the forecast area. && .SHORT TERM /SUNDAY THROUGH TUESDAY/... A flat H5 ridge axis is forecast to move across the region on Sunday. Subsidence underneath the ridge axis should be an inhibiting factor for convection initiation, especially for the central and southern Midlands as well as the CSRA. The Northern Midlands could be close enough to disturbances moving into the Mid Atlantic States for a greater chance of convection. The atmosphere remains moist and unstable area wide with afternoon SBCAPE values in excess of 1500 J/KG and PW values around 1.5 inches. The Eastern U.S. undergoes a major pattern changes Memorial Day through Tuesday with an unseasonably strong upper low moving into the Great Lakes region. The Midlands and CSRA will begin to experience H5 height falls on Memorial Day and continue into Tuesday. An unstable and moist airmass will be over the region on Memorial Day with afternoon SBCAPE values around 2000 J/KG and PW values up to 1.75 inches. A cold front approaches the region in the late afternoon or evening time frame. The forcing is not lined up time wise with the best instability. SPC has our region in a Marginal Risk of severe weather on Memorial Day with a Slight Risk over much of North Carolina. The Slight Risk could be extended southward during the next update. Damaging wind gusts are the primary concern. A cold front moves across the region Monday Night before stalling offshore on Tuesday. PW values decrease to below one inch during the day with dew points dropping into the 50s. If this forecast solution verifies, cooler and much drier conditions push into the region. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... Ensembles depict a high probability of much below normal H5 heights across the Eastern U.S. next week. This should allow Canadian surface high pressure to move into the region Tuesday Night through the end of the week. Temperatures and dew points should be below normal with dry weather. && .AVIATION /16Z SATURDAY THROUGH WEDNESDAY/... VFR conditions expected outside of showers-storms. Thunderstorms expected at AGS and DNL this afternoon. A line of strong thunderstorms is moving across central GA and will likely impact the Augusta area terminals between 18z and 22z with gusty winds and associated vsby-cig restrictions. Some isolated showers and storms are expected across GA-SC this afternoon behind and away from this line of storms, but confidence is too low for TAF mention elsewhere. Convection should settle down later this evening and is not expected overnight into Sunday. Fog-stratus is possible overnight and especially in areas with rainfall, so typical areas like AGS and OGB will likely have some vsby-cig restrictions into Sunday morning. EXTENDED AVIATION OUTLOOK...Restrictions possible at times through early next week in afternoon and evening showers and thunderstorms. && .CAE WATCHES/WARNINGS/ADVISORIES... SC...None. GA...None. && $$ SYNOPSIS... NEAR TERM... SHORT TERM... LONG TERM... AVIATION...