Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 02/19/24


Area Forecast Discussion
National Weather Service Jacksonville FL
636 PM EST Sun Feb 18 2024 ...New UPDATE... .UPDATE... Issued at 632 PM EST Sun Feb 18 2024 For the latest NE FL and SE GA Daily Key Messages please visit: https://www.weather.gov/media/jax/briefings/nws-jax-briefing.pdf The widespread light rain over eastern counties will end around midnight, as the low wraps up off the east coast of FL. Cooler and drier air will advect into region from the northwest overnight, which could lead to a little patchy frost for far inland SE GA around dawn. && .SHORT TERM... (Monday through Tuesday night) Issued at 136 PM EST Sun Feb 18 2024 The tight local gradient begins to relax as a surface low northeast of the Bahamas shifts further into the Atlantic and weak high pressure builds down the eastern seaboard. Showers lingering across coastal St Johns and Flagler counties Monday morning will finally move offshore bringing an end to this weekend`s showers. A cold, dry airmass settles over the region for early week. With skies clearing, daytime heating will allow temperatures to warm into the 60s. However, calm and clear skies overnight will allow for good radiational cooling with lows dipping into the 30s inland and low 40s along the coast. Patchy to areas of frost will be possible early Tuesday and Wednesday mornings. A Frost Advisory may be needed for inland SE GA for Tuesday morning where areas may dip into the low 30s leading to widespread frost. && .LONG TERM... (Wednesday through next Sunday) Issued at 136 PM EST Sun Feb 18 2024 Dry conditions continue as high pressure ridging along the eastern seaboard begins to weaken and retreat due to a strong cold front moving across the central US. Flow shifts to southwesterly ahead of the next system ushering in moisture and further warming. Temperatures warm to above normal with highs reaching the 70s Thursday and Friday. Showers return on Friday as the cold front moves across the region. Instability appears to be limited but an isolated thunderstorm can`t be ruled out along the front. Breezy to gusty westerly winds will be possible ahead of and along the front where gusts could potentially reach 30-40 mph. A secondary dry cold front will pass through on Saturday with high pressure building in for the weekend. && .AVIATION... (00Z TAFS) Issued at 603 PM EST Sun Feb 18 2024 While VFR conditions will persist this TAF period at KSSI, the low ceilings in light rain will be slow to lift at the remainder of the area TAF sites. The rain is expected to end around midnight. Ceilings will then slowly lift to VFR during the early morning hours on Monday. Winds will be elevated along the coast this evening, especially at KSGJ. && .MARINE... Issued at 136 PM EST Sun Feb 18 2024 Latest 12Z model runs of GFS/NAM and updated HRRR have been consistent on placing 25-30 knot N-NE winds on the NW side of intensifying low pressure system off the FL East Coast tonight, so have upgraded to a Gale Warning for a portion of the NE FL coastal waters, while leaving Small Craft Advisory in place for the rest of the NE FL and all of SE GA coastal waters for the strong N-NE flow. Models still on track for winds/seas starting to subside late on Monday into Tuesday as low pressure system tracks away from the region, then the local waters should remain headline free on Wednesday/Thursday as high pressure builds into the region. Next round of potential Small Craft Advisory conditions can be expected Friday as strong cold frontal passage still on track to pass through the coastal waters Rip Currents/Surf: Strong N-NE flow will continue a High Risk of rip currents along the NE FL coastline through Monday with surf/breakers of at least 4-6 ft, and will place High Surf Advisory for the NE FL coastline south of St Augustine for building surf to 5-7 ft tonight into Monday. Moderate risk with lesser surf/breakers of 2-4 ft along the SE GA coast. && .PRELIMINARY POINT TEMPS/POPS... AMG 35 63 33 66 / 10 0 0 0 SSI 46 61 41 62 / 50 10 0 0 JAX 44 63 38 65 / 70 10 0 0 SGJ 49 62 43 64 / 90 40 0 0 GNV 44 65 37 68 / 80 10 0 0 OCF 47 66 38 68 / 80 10 0 0 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...High Rip Current Risk through late Monday night for FLZ124-125- 133-138. High Surf Advisory until 5 PM EST Monday for FLZ133-138. GA...None. AM...Small Craft Advisory until 7 AM EST Monday for AMZ450. Small Craft Advisory until 10 PM EST Monday for AMZ452-470. Gale Warning until 7 AM EST Monday for AMZ454-472-474. Small Craft Advisory from 7 AM Monday to 7 AM EST Tuesday for AMZ454-472-474. && $$
Area Forecast Discussion
National Weather Service North Platte NE
556 PM CST Sun Feb 18 2024 .KEY MESSAGES... - Little or no rain or snow is expected across wrn/ncntl Nebraska during the next 7 days. - Storm systems affecting the West Coast will present highs in the 60s across parts of wrn and ncntl Nebraska Tuesday and Wednesday, and again next Saturday and Sunday. && .SHORT TERM /THROUGH MONDAY NIGHT/... Issued at 324 PM CST Sun Feb 18 2024 An upper level disturbance across nrn UT this afternoon will move slowly east through Nebraska tonight and Monday morning. The upper level moisture is robust as it crosses Nebraska but the RAP model shows dry air below 600mb. The best we would expect from this disturbance would be sprinkles. No other disturbances are expected tonight through Monday night. The temperature forecast leans on the short term model blend plus bias correction. This strategy appears to respect melting snow with highs in the 40s across the north and 50s south Monday. A check on the NAM model soundings suggests mixing heights near 850mb north and 750mb south. Nighttime lows are in the 20s both nights. Monday night would be the radiation night with light winds. Temperatures aloft at h850mb are 5- 10C and this should prevent lows in the teens. Wrn and ncntl Nebraska will be post-frontal Monday and the wind forecast is close to 15 to 20 mph with gusts 25 to 30 mph. The forecast lines up with the 500m AGL winds of around 17kts. && .LONG TERM /TUESDAY THROUGH SUNDAY/... Issued at 324 PM CST Sun Feb 18 2024 The last of a series of strong upper lows will affect the West Coast later this week. The system affecting the area today will move inland and reach wrn and ncntl Nebraska as an open wave Wednesday. A surge of warm air will precede the disturbance before it reaches Nebraska. POPs for showers are in place and confined to just swrn Nebraska and the srn Panhandle for this forecast. The system is lacking focus for low level moisture pooling. There are no other rain chances in the forecast. Attention is drawn toward the temperature forecast and the models continue to advertise highs in the 50s and 60s Tuesday and Wednesday. By this time the snow cover should be melted supporting mixing heights around 750mb across nrn Nebraska but there is the potential for bouts of mid and high level clouds. The NAM and GFS soundings show this up at KVTN with mixing heights to just h850mb. highs in the 50s are in place in this area. A weak cold front will drift into the region Wednesday night and temps at h850mb drop about 5C. This knocks highs back into the 50s through wrn/ncntl Nebraska. The models are in very good agreement showing temperatures gradually warming back to near 60 by next Saturday. 60s are in place next Sunday as temperatures at h850mb warm to 10-15C. By next weekend, another strong upper low should be pushing into the West Coast and this will send a surge of warm air across the Rockies into Nebraska. && .AVIATION /00Z TAFS THROUGH 00Z TUESDAY/... Issued at 528 PM CST Sun Feb 18 2024 VFR conditions are still expected to persist through the forecast period. Passing high clouds will remain prevalent with winds initially out of the south, becoming more westerly and then northwesterly by late in the period. Afternoon gusts on Monday may approach 25 knots across much of the area include at either terminal. && .LBF WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...CDC LONG TERM...CDC AVIATION...NMJ