Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/01/22

Area Forecast Discussion
National Weather Service Charleston SC
1033 PM EST Mon Feb 28 2022 .SYNOPSIS... High pressure will build into the region tonight and remain the dominant feature for most of this week. Late this week, a large low pressure system will organize over the Central Plains, lifting a warm front north of the region this weekend into early next week. && .NEAR TERM /THROUGH TUESDAY/... The trough in the mid levels is offshore and heading due east, taking with it much of the deep moisture. The Charleston sounding from 00Z has PWat down to 0.44 inches, which is 0.75 inches less than last night at the same time. The HRRR has been showing a small chance of a few showers redeveloping near or onshore overnight. But this scenario seems unlikely given minimal moisture and convergence, plus isentropic downglide. Instead there will be some stratocumulus that develop and/or advect onshore, with thin cirrus that arrives with the sub tropical jet overnight. Recent satellite trends have shown more clearing than originally expected, and thus some places will get a bit colder. In fact there could be a little frost in northern berkeley County, where a few places could dip into the mid 30s. Previous discussion... The mid level trough will pull offshore this evening and then further out to sea thereafter. This allows for surface low pressure off the coast of Daytona Beach and Cape Canaveral to deepen a bit as it shifts further out into the ocean through the night. Wrap around moisture from the feature will also decrease locally, and as PVA weakens and gives way to NVA and coastal convergence slackens, the risk for any showers looks to stay over the Atlantic through the night. There will be an increase in cloud cover over coastal sections due to stratocumulus advecting onshore within a low level east to northeast flow, and then from some late night cirrus in response in a weak and elongated short wave. On average skies will be mostly clear or partly cloudy well inland and partly to mostly cloudy closer to shore. Due to large dew point depressions and winds slackening off inland, we look to get enough cooling to drop lows near or even a tad below climo. Coldest spots will be over the northwest counties, with the warmest along the barrier islands where mixing persist through the night. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/... Tuesday: Sfc high pressure centered over the lower Mississippi River Valley will build east across the region through the day. The forecast area will remain under a broad trough aloft, with the trough axis over the western Atlantic. The dry NW flow aloft will result in decreasing cloud cover through the day. Temperatures are expected to peak in the low 70s across SE GA to the upper 60s across the CHS Tri-county. Wednesday: Warm and dry conditions expected. Mid-level zonal heights and ridging sfc high pressure will remain across the forecast area. High temperatures are expected to range in the mid to upper 70s. The mild temperatures should result in mixing heights are forecast to deepen to 4 kft or more. As a result, sfc dewpoints should lower into the low to mid 30s, with RH values across inland GA and SC falling into the low to mid 20s. Thursday: A dry backdoor cold front will approach the CWA from the north during the daylight hours. With the front remaining just north of the forecast area, high temperatures should easily reach around 80 degrees. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... Long term guidance indicates that the backdoor cold front will push over the forecast area late Thursday night into Friday morning, contributing very little cloud cover. An area of low pressure will organize and deepen over the Central Plains late this week, tracking to the NW over the Mid West this weekend. The backdoor cold front over the region on Friday, will lift north as a warm front later this week. A cold front associated with the Mid West low is expected to sweep across the Mississippi River by Monday. This pattern should provide the region with gradual WAA this weekend into early next week. High temperatures should warm each day, reaching the mid to upper 80s on Monday. && .AVIATION /03Z TUESDAY THROUGH SATURDAY/... VFR looks to prevail with the 00Z TAF set at KCHS, KJZI and KSAV. However, we will need to carefully watch for a period of marginal MVFR ceilings overnight into Tuesday morning due to a persistent onshore flow. Extended Aviation Outlook: VFR. && .MARINE... Overnight: About a 2-3 millibar spread will exist across the local waters between high pressure to the north and low pressure off the Florida coast. This will support NE winds as high as 20-25 kt and gusty over the ocean, and thus a continuation of the Small Craft Advisories. Charleston Harbor will have a bit more slack gradient, but still enough for NE winds up to 15 kt. A favorable fetch will allow for elevated seas to persist, still as high as 4-6 feet within 20 nm and up to 7 or 8 feet on the over Georgia waters. Tuesday through Saturday: Small Craft Advisory conditions will persist through Tuesday morning across all waters outside the Charleston Harbor, with 6ft seas and wind gusts in the low 20 knots to around 25 knots. Conditions will likely improve within the nearshore waters Tuesday afternoon, with conditions across the offshore GA waters improving by daybreak Wednesday morning. Quiet marine conditions are expected thereafter as high pressure builds in at the surface. && .TIDES/COASTAL FLOODING... The combination of astronomical forces and gusty northeast winds will result in a continuation of elevated tides overnight and Tuesday. Looking at anamolies the past four high tides, departures have been around 0.8 to 1.0 ft MLLW above predicted. If this trend were to continue it would produce minor coastal flooding with the 7 AM high tide in Charleston and coastal Colleton. If winds don`t back too much northerly with land breeze influences, tide levels might even be higher. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...Small Craft Advisory until 1 PM EST Tuesday for AMZ350-352-354. Small Craft Advisory until 7 AM EST Wednesday for AMZ374. && $$ NEAR TERM... SHORT TERM...NED LONG TERM...NED AVIATION... MARINE... TIDES/COASTAL FLOODING...
Area Forecast Discussion
National Weather Service North Platte NE
551 PM CST Mon Feb 28 2022 .SHORT TERM...(This evening through Tuesday night) Issued at 336 PM CST Mon Feb 28 2022 Northwest flow aloft continues tonight through Tuesday night and the extensive area of mid and high clouds across the northwest U.S. shown on satellite will remain mostly north of wrn and ncntl Nebraska during this time. A weak sfc trof of low pressure will move through the region tonight. This will cause an increase in moisture with precipitable water increasing to 0.40 inches by morning. The atmosphere should remain mixed and the RAP model shows h850mb winds increasing to 30 to 45 kts-from the northwest. These winds will decrease during the day Tuesday but moisture will continue to increase with precipitable rising to near 0.50 inches by late afternoon. The temperature forecast tonight and Tuesday uses a blend of the guidance and the 50th percentile of the NBM for lows in the mid 20s to lower 30s and highs in the mid 60s to lower 70s. Temperatures continue to warm aloft Tuesday night and precipitable water remains nearly static at 0.50 inches. This would seem to support warmer lows in the upper 20s to mid 30s as suggested by the short term model blend. .LONG TERM...(Wednesday through Monday) Issued at 336 PM CST Mon Feb 28 2022 Back to back storms will cross the cntl Plains Friday night- Saturday and then Sunday-Sunday night. The GFS will track both systems through nwrn Nebraska and then through SD while the ECM tracks both systems through the heart of wrn and ncntl Nebraska. The ensembles are generally similar with the track with minor north and south differences. There is little change in the temperature forecast Wednesday. A slight mark up is in place using the guidance blend and the 50th percentile of the NBM. This suggested highs in the upper 60s to mid 70s. A back-door cold front will drop through wrn and ncntl Nebraska Wednesday night. The models are a little faster with the front and this could affect the temperature forecast Wednesday across ncntl Nebraska. The models are also trying to erode the cold air in place Friday. This seems fishy given it is modified arctic air. Highs in the 50s and 60s are in place across wrn and ncntl Nebraska Friday. A check on the ECM thunderstorm forecast Friday indicates the better chances will be across nrn KS and areas generally south of Interstate 80 in Nebraska. These storms, if the form, will likely focus on the sfc cold front which will be across KS. Otherwise, the rain-snow forecast continues pretty much on track. The models are slowing the onset of the precipitation down slightly but the best chance continues to be Friday night and Saturday. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 548 PM CST Mon Feb 28 2022 VFR conditions will prevail through the next 24 hours. There will be some LLWS that moves in overnight, with gust of 35 kts, generally closer to midnight and before sunrise. Surface winds will remain light through the evening and overnight out of the west to west northwest, with wind speed under 10 kts. Tomorrow afternoon winds will become breezy across the northern Sandhills into north central Nebraska with some locations seeing gust up to 25 kts. Winds will remain out of the west northwest tomorrow afternoon. && .LBF WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...CDC LONG TERM...CDC AVIATION...Gomez
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