Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/29/21


Area Forecast Discussion
National Weather Service Charleston SC
1023 PM EDT Thu Oct 28 2021 .SYNOPSIS... A low pressure system will impact the region through tomorrow. High pressure will return on Sunday and prevail through the middle of next week. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... The last of the heavier and steadier rains will pull north of the Santee River by midnight with the passage of the triple point. There can still be a few showers through the overnight in various places due to the approach of the mid and upper level low, but coverage will be sparse. There has been enough clearing and a significant drop off in winds where we have patchy fog through 12-1 am. Locally dense fog is possible but not enough for a Dense Fog Advisory. Drier air will steadily advance into the area from the southwest, and as winds aloft align themselves more with surface winds and some cool advection develops, there is also more mixing as surface winds increase again. Depending upon the strength of the cool advection and the amount of clearing, min temps are a challenge. We will go with a blend of the NBM, HRRR, RAP and MOS, arriving at a large range from lower 50s across far interior Georgia, to the mid and upper 50s most elsewhere, except 60-64F along the barrier islands and across most of Charleston County. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/... An impressive deep surface low extending into the upper levels over the Tennessee Valley will slowly track northeast through the period, eventually transitioning into a open wave over the New England region Sunday. The forecast area remains in a somewhat dry slot Friday and Saturday with much of the moisture/rain focused to our west over the SC/GA Midlands as well as offshore to our east. Isolated showers could breach the extreme inland counties and the coastline, mainly in the afternoon hours Friday and Saturday. Thus, POPs feature values between 10-15% across these areas. Sunday will remain precip-free as dry surface high pressure builds in from the west. High temperatures Friday will range in the mid 60s inland to low 70s along the immediate coast. Saturday will be a couple of degrees cooler before warming on Sunday into the low 70s with nearly full sunshine across the forecast area. The forecast features low temps in the upper 40s most places and low to mid 50s along the coast. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... High pressure will remain the dominant surface feature through much of the period. Drier air and a lack of any notable forcing mechanisms will support a rain-free forecast each day. A weak cold front associated with an upper disturbance could approach the region around the middle of next week. For now, guidance shows the greatest moisture north of the region, which could maintain the dry forecast into next weekend. High temperatures are expected to be near normal with slightly above-normal min temps. && .AVIATION /02Z FRIDAY THROUGH TUESDAY/... The remains a risk for MVFR conditions either in light fog and/or lower ceilings early tonight, and again briefly in any isolated -SHRA/SHRA that might occur in association with an approaching upper level low through Friday. Otherwise, mainly VFR will prevail. We have low level wind shear at all three sites early tonight now that surface winds have calmed down, but strong winds remain in the lower levels. Winds are expected to increase again overnight or early Friday, and continue through most of the remainder of the 00Z TAF cycle. This is the combination of a tight gradient, rising pressures and a higher mixing height. Extended Aviation Outlook: VFR conditions are expected through the middle of next week. && .MARINE... Overnight: The last remaining Gale Warning for AMZ350 will come down at midnight, as the gradient has finally eased enough and mixing is tempered somewhat by neutral or slight warm advection. The other waters have improved enough where we have Small Craft Advisories in effect, and once the Gale comes down, it will also join the other waters with a Small Craft Advisory. Late in the overnight period there is another surge as cool advection develops and isallobaric pressure rises coincide with a tightening of the gradient. This could result in a marginal Gale Warning. Seas that have been elevated will be very slow in coming down, dropping only about a foot or so through the night. Friday through Tuesday: Elevated winds and seas will persist on Friday with Small Craft Advisories (SCAs) continuing across all marine zones. We have extended the SCA for the Charleston Harbor through Friday evening for gusts up to 25 kt. Conditions are expected to improve Friday night as winds and seas decrease, with SCAs over the Beaufort/Colleton County waters and GA waters out 20nm, and the Charleston Harbor coming down Friday night. The remaining SCAs are expected to come down by Saturday morning, though winds will likely remain in the 15-20 kt range through the day. No marine concerns early next week as high pressure expands over the region. Rip currents: Gusty winds and longer period swell (11-12 seconds) will lead to an elevated risk of rip currents Friday and Saturday. A Moderate risk of rip currents is forecast for both days. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...Small Craft Advisory until 8 PM EDT Friday for AMZ330-352. Small Craft Advisory until 8 AM EDT Saturday for AMZ350. Gale Warning until midnight EDT tonight for AMZ350. Small Craft Advisory until 8 AM EDT Saturday for AMZ374. Small Craft Advisory until 8 PM EDT Friday for AMZ354. && $$ NEAR TERM... SHORT TERM...BRM LONG TERM...BRM AVIATION... MARINE...
Area Forecast Discussion
National Weather Service Grand Forks ND
1058 PM CDT Thu Oct 28 2021 .UPDATE... Issued at 1055 PM CDT Thu Oct 28 2021 The main concern for the overnight period will be potential and timing of fog set up. Mist developed across the northern valley for about two hours, however enough mixing with the NW winds helped it erode with this last set of obs. Stratus ahead of a Warroad to Sabin MN line will continue to move east leaving clearing skies in its wake. As the surface ridge slides east, winds will continue to decrease and enhance radiational cooling. Models continue to target mainly NW MN (east of the valley) for fog development by around 07Z. Have adjusted Wx grids for a bit more fog coverage tonight, and will need to monitor for potential headlines closer toward morning. && .SHORT TERM...(This evening through Friday night) Issued at 234 PM CDT Thu Oct 28 2021 Minimal impacts in the short term with high pressure ridge axis traversing the area tonight. That said there is the possibility of another night or morning of some fog impacts across portion of NW MN as light winds and clear skies allow for radiational fog development. Given the clouds today, recent rainfall and saturated blyr persisting will add the fog mention from late tonight through the morning commute Friday along the eastern edge of the RR valley and into lakes country for portions of MN. Tomorrow will see increasing mixing from west to east during the day as southerly flow develops in response to developing low pressure over the high plains. This mixing will bring highs to near 60 in the west to low 50s east. Friday night will be the last night above freezing with the southerly winds persisting and temps holding in the upper 30s. .LONG TERM...(Saturday through Thursday) Issued at 234 PM CDT Thu Oct 28 2021 Principal chances for impactful weather really aren`t presenting too much as we head into a tranquil a cooler weather period to begin November. Sat offers best pcpn chances as a wave/sfc cold front moves from DVL early in the day to WC MN by late aftn/eve. Winds will shift to the W and NW and become breezy behind the feature, but little if any pcpn is likely along with it. Flow will be generally NW from this point on, bringing dry and cooler weather to the forecast area. To wit : 850 mb temps dipping below freezing more consistently yielding overnight lows well down in the 20s with corresponding afternoon maxima limited to the 30s. && .AVIATION...(For the 06Z TAFS through 06Z Friday night) Issued at 1055 PM CDT Thu Oct 28 2021 The back edge of the stratus has cleared TVF and should be through BJI by midnight (05Z), definitely by the time the 06Z TAFs go into effect. So think all sites will start off VFR (possible exception of MVFR vsbys at TVF), with TVF/BJI seeing vsbys drop rapidly somewhere in the 08Z to 10Z timeframe. Expect IFR cigs for early morning flights as FG develops. Models area a bit slow dissipating FG tomorrow morning, so late morning is possible and will lean towards worse case as no strong confidence of a rapid burnoff after sunrise. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...None. MN...None. $$ UPDATE...Speicher SHORT TERM...JK LONG TERM...WJB AVIATION...Speicher
Area Forecast Discussion
National Weather Service Sacramento CA
231 PM PDT Thu Oct 28 2021 .SYNOPSIS... Dry and mild weather through Friday. A weather system moving over the far northern portion of California will bring a chance of showers late Friday and Saturday, mainly to the northern mountains and northern Sacramento Valley. Rain returns to the majority of Northern California early next week. && .DISCUSSION... Fog and low stratus continued to build north into the northern San Joaquin Valley and Sacramento Valley this morning, as far north as the Sacramento metro area, and slowly dissipated through the morning hours. The fog/stratus kept temperatures dampened in the mid 60s through early afternoon in affected areas, whereas temperatures in the far northern Sacramento Valley rose quickly to the 70s. However, temperatures are bouncing back as high pressure remains situated over California. Valley temperatures are forecast to top out in the low 70s to near 80s across the Valley today and tomorrow with 50s to 60s in the mountains and foothills. HREF and HRRR guidance suggest patchy fog is possible once again tomorrow morning in the Valley, mainly near and south of the Sacramento area. Ensemble guidance remains on track with a tight, closed upper low approaching the forecast area tomorrow, bringing precipitation chances late tomorrow night into Saturday. Guidance continues to slow the weather system, and members are becoming more in agreement on the timing. Precipitation chances are limited to the Coastal Range, northern Sacramento Valley, Southern Cascades, and adjacent foothills as the southern edge of the low brushes through the forecast area. This system is looking a little more convective in nature, with a chance of isolated thunderstorms on Saturday. QPF amounts have increased slightly due to the convective nature of this system. Precipitation amounts of 0.1 to 0.6 inch are forecast, with the heaviest amounts expected in Shasta County. Ensemble guidance has the upper low moving out of the forecast area by Sunday as another longwave trough approaches the West Coast, bringing dry weather to interior Northern California for Halloween. Temperatures will cool to around 5 to 10 degrees below normal Saturday and Sunday with Valley temperatures in the 60s and mountains and foothills in the 40s to low 60s. -HEC && .EXTENDED DISCUSSION (Monday THROUGH Thursday)... Unsettled weather is forecast to continue through the extended period as ensemble guidance shows longwave troughing continuing in the Eastern Pacific through next week. Guidance is in good agreement of a deeper wave brushing across northern California on Monday. IVT forecast indicates it will tap into some tropical moisture, bringing more widespread precipitation across the forecast area. However, the front is expected to weaken as it makes landfall as the main trough only brushes the forecast area, so QPF amounts will be more limited than if the trough fully hit the forecast area. Precipitation amounts in the Valley are only around 0.1 to 0.3 inch with 0.25 to 1 inch in the mountains and foothills, mainly north of Highway 50. This will be a warm system with snow levels above 7,500 to 8,000 feet. Weak ridging takes over on Tuesday, then ensemble guidance indicates another upper trough approaching the coast Wednesday. Timing and strength is still uncertain at this point, but guidance brings in another round of precipitation in the Wednesday/Thursday timeframe with this system. Temperatures through the week will remain below normal with Valley in the 60s and 40s to 60s in the mountains and foothills. -HEC && .AVIATION... VFR conditions next 24 hours expect local MVFR/IFR possible in BR/FG from KCIC southward between 06z-18z Friday. Surface winds remain under 12 knots. && .STO WATCHES/WARNINGS/ADVISORIES... None. && $$
Area Forecast Discussion
National Weather Service Topeka KS
909 PM CDT Thu Oct 28 2021 .UPDATE... Issued at 909 PM CDT Thu Oct 28 2021 Cancelled the Wind Advisory. Winds continue to diminish this evening and have fallen below advisory criteria. Sustained winds around 20 mph with gusts around 30 mph will remain possible through the overnight hours. && .DISCUSSION... Issued at 244 PM CDT Thu Oct 28 2021 19Z water vapor imagery and profiler data show a closed upper low over central MO slowly lifting north. The surface low with this system was centered over southwestern MO. The strong pressure gradient associated with the low pressure system has caused north winds to gust between 30 and 50 MPH pretty consistently across the forecast area today. Further west water vapor imagery showed shortwave ridging over the southwestern U.S. extending up into the northern Rockies. Another upper trough was noted off the west coast of North America. Models are in good agreement with the overall slow progression of the low pressure system just west of the forecast area. This keeps the upper level deformation and deeper moisture over far eastern KS for much of the night. So the light rain and overcast skies are forecast to continue through a good portion of the night. There could be some light rain over eastern parts of Anderson and Franklin counties through the mid morning hours Friday. The other sensible weather will be the continued gusty winds through the night. The RAP and HRRR want to keep wind gusts around 45 MPH into the evening, high enough that I`ve considered extending the wind advisory. Would like to say the pressure gradient relaxes a little overnight, but the RAP and NAM both maintain the pressure gradient near the current strength. And the RAP and HRRR show stronger wind gusts expanding in area overnight. So will go ahead and extend the advisory through tonight for the eastern two thirds of the forecast area where the RAP/HRRR show the stronger gusts persisting. Shortwave ridging is expected to move over the area by Saturday with clear skies. This looks to create good conditions for radiational cooling Saturday morning as winds at the surface become light and variable. Because of this have inserted areas and widespread frost across much of the forecast area with lows likely in the lower to middle 30s. Will probably need a frost advisory and freezing warning for parts of the area Saturday morning. Temps should warm somewhat Saturday afternoon as southerly winds bring some warmer air north ahead of the next cold front Saturday night. There isn`t much moisture or forcing for the front to produce any precip. Increasing cold air advection for Sunday is expected to keep highs in the lower and middle 50s. The next chance fore precip looks to come Monday as models hint at some mid level frontogenesis moving in from the northwest as a weak PV anomaly passes overhead. Mid levels look to saturate enough for some light precip. Temps in the lower troposphere look to remain warm enough for precip to mainly be in the form of rain, but temps aloft look cold enough that there could be some wet snowflakes mix in early in the morning. Northerly winds and limited insolation are likely to keep temps in the 30s and 40s for Monday. There may be a break in precip Tuesday before another shortwave passes aloft Tuesday night. There are indications for moisture to possibly be lifted back north of the surface front Tuesday night. However the surface front is progged to be in central OK and that seems like a long way for moisture to make it this far north. Because of this there are only some small POPs (20 to 30 percent) across east central KS. Both the ECMWF and GFS take the surface front well south of the forecast area by Tuesday and keep it south through the end of the forecast period. So confidence in the chances for precip after Monday evening are low thinking moisture would be pretty limited this far north into the surface ridge. Northerly winds through the middle of next week are likely to keep temperatures below normal. In fact areas across northern KS could see a hard freeze next week. With the local growing season considered to be over after October 31, I don`t anticipate the need for frost or freeze headlines next week with the colder temperatures. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 620 PM CDT Thu Oct 28 2021 VFR at KMHK through the TAF period with gusty north winds through tomorrow morning. MVFR at KTOP/KFOE with gusty north winds through tomorrow morning. VFR at KTOP/KFOE thereafter. Rain will diminish this evening from west to east and finally move out of the area by tomorrow morning. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Jones DISCUSSION...Wolters AVIATION...Jones
Area Forecast Discussion
National Weather Service Tulsa OK
1015 PM CDT Thu Oct 28 2021 .DISCUSSION... Have allowed all wind advisories to expire, as most gusts have fallen below 40 miles an hour. Every now and then, an isolated 40+ mile an hour gust appears, but they have been few and far between since the sun has set. Scattered to numerous showers continue to move south across northeast Oklahoma and northwest Arkansas, mainly to the east of Highway 75, and the latest HRRR says this trend will continue for much of the rest of the night. Have expanded low pops west a bit in the 06-12Z period to account for this. The clearing line has moved little this afternoon and evening, and have raised cloud cover overnight in most places. Also raised overnight lows a couple degrees. Update has already been sent. && .PREV DISCUSSION... /Issued 649 PM CDT Thu Oct 28 2021/ AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG. Northwest Arkansas TAF Sites...IFR/MVFR conditions along with scattered rain showers and breezy/gusty winds will remain common tonight and into Friday as the backside of the upper low continues push off to the east. During the afternoon hours Friday...conditions look to be more MVFR to low end VFR through the end of the period. Eastern Oklahoma TAF Sites...some scattered rain showers maybe possible into the overnight period otherwise broken VFR conditions and breezy/gusty winds are forecast. Late tonight into Friday morning there could be a period of MVFR conditions and will carry tempo groups for Northeast Oklahoma. During the day Friday...conditions are expected to lift back to VFR by mid/late morning with cloud cover scattering out during the afternoon hours behind the exiting upper low. PREV DISCUSSION... /Issued 157 PM CDT Thu Oct 28 2021/ DISCUSSION... Gusty conditions persist this afternoon as strong northwesterly winds wrap around the vertically-stacked cyclone currently across southwestern MO. Have observed frequent gusts around 40-45 mph across parts of eastern OK, with an occasional 50+ mph gust (highest so far in our area has been a 53 mph gust at the Foraker mesonet site in Osage county). Thicker cloud cover farther east has limited the mixing and kept winds a bit in check, but still seeing gusts of 35-40 mph for the bulk of eastern OK/northwest AR. Wind Advisory products are scheduled to expire at 00Z for eastern OK and 03Z for northwest AR. It`s possible these will need to be extended and will defer this decision to the evening shift. Otherwise, areas of mostly light showers will linger through the night, with precipitation tapering off across northwest AR on Friday. Milder weather is forecast for the weekend as mid-level heights rise in the wake of the exiting cyclone. Halloween weather is looking great, with highs in the 60s/lower 70s and temperatures falling into the upper 40s/mid 50s during the evening. The initial wind shift associated with the next front will sag through the area on Sunday, with deepening cooler air expected to hold off until early next week. Rain chances could arrive as early as late Monday, with the better chances expected later Tuesday into Wednesday as a stronger wave zips across the region in the southern stream. Temperatures are expected to remain below normal, with highs generally in the 50s and lows in the 30s/40s. Could see our first light freeze late in the week for parts of northeast OK and northwest AR. && .TSA WATCHES/WARNINGS/ADVISORIES... OK...None. AR...None. && $$ SHORT TERM...20 LONG TERM....05 PLATE