Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/11/22

Area Forecast Discussion
National Weather Service Columbia SC
746 PM EST Thu Mar 10 2022 .SYNOPSIS... A boundary remains over the area with rain showers possible through the end of the week. A strong cold front and low pressure system will develop and move through early Saturday, bringing the risk of severe weather. Windy conditions expected behind the front Saturday before a major cool down with morning lows below freezing Sunday. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... Surface high pressure over the Mid-Atlantic will continue to direct NE low level winds into the forecast area. Low level moisture will stay locked in place through the night with overcast or mostly cloudy skies. Measurable rainfall is unlikely overnight though, since the deeper moisture has moved out of the area. There may be some clearing in the northern Midlands where moisture will be shallow. If this occurs, the HRRR indicates that fog may develop near the NC/SC border. Lows will be mild due to cloud cover and high dewpoints. Expect temperatures overnight to be in the mid to upper 40s. Some spots in the northern Midlands may dip into the low 40s if cloud cover decreases. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/... Friday: The wedge will continue to influence the weather for the day on Friday. Low clouds will be firmly entrenched over the area. The big question is if the in situ wedge breaks Friday with a large spread among models differing on this solution. Traditionally the models do not handle the breakdown of the wedge well and are too quick in the process. Forecast soundings do appear that the GFS is a bit too eager to mix out the low clouds but the high pressure is not in a favorable location for the wedge to continue through the day. However, think it will be hard to dislodge given the wind direction/speeds through the day and warm frontal boundary sluggishly moving northward. The caveat will be that the precipitation will be moving in during the mid/late portion of the day which could help weaken the wedge. For now will stay lower than most of the guidance and keep the wedge in for much of the day. Friday Night: A strongly amplified trough to the west will begin to move towards the area. The surface low that developed along the Gulf Coast will strengthen considerably with an immense amount of upper divergence courtesy of a 150 knot jet streak. Strong SW flow will allow PWATs to increase significantly, approaching the climatological max over the area, comparing to CHS sounding climo. With 850mb winds increasing to around 60 to 70 knots late and 500mb winds around 85 knots across the area, there will be plenty of shear to support severe weather as the surface low tracks through the Upstate and associated cold front moves through the area. The question will be if storms will be surface based, which by the nature of the timing of the arrival of this low, is not climatologically favored. As we start to enter HiRes model territory there are some concerns working against instability becoming surface based with convection depicted in multiple CAMS ongoing across south GA and the FL panhandle which would limit surface destabilization in our area. While thunderstorms are likely, at this point they do appear to be more elevated. The models continue to show a surge of instability late Friday night/early Saturday morning of CAPE and LI`s up through the CSRA and into the eastern half of the CWA. This continues to be a setup worth watching for a conditional damaging wind gust and tornado threat. Any convection that does develop will produce downpours, but the speed at which storms will be moving will limit any flooding concerns. As for temperatures overnight, expect a gradual rise in temperatures after midnight as the warm front gets a surge from the increasing s/sw wind field ahead of the cold front. Expect the low temperature to occur during the evening hours. Saturday: Some timing differences among models and the thunderstorm threat will likely linger into Saturday morning. Notable for the day is the high will be observed across the area in the morning as a modified arctic airmass will move in behind the cold front with strong cold advection. Expect morning temperatures to be in the upper 50s/lower 60s ahead just prior to the arrival of the cold front. Tight pressure gradient and soundings indicate very gusty winds behind the front. The winds at times on Saturday from mid morning through mid afternoon may approach wind advisory criteria with strong consensus among models of at least occasional gusts above 40 mph, especially in the CSRA. Cold air will continue to funnel into the area into Saturday night with temperatures expected to drop well below freezing. Fairly tight spread among SREF members of temperatures dropping into the 20s across the area. Due to the expect drop in temperatures due to CAA and weakening wind field a Freeze Watch has been issued for Saturday night into early Sunday . Expect temperatures to be in the lower to middle 20s. && .LONG TERM /SUNDAY THROUGH THURSDAY/... In the long term, there appears to be one more cold morning across the Midlands and CSRA as high pressure gradually slides east and off the Carolina coast by Monday morning. Another Freeze/Frost product may be necessary for Monday morning. For the remainder of the period, the long term shows limited spread in temperatures among blended guidance and fairly decent predictability. High pressure will be over the area and quickly move offshore as temperatures moderate with EC ensemble mean supporting a return to zonal flow and weak ridging by the end of the period. Moisture will begin to return, although there is quite a bit of uncertainty in the extent with fewer EC ensemble members quite as bullish compared to the GEFS suite. Relatively benign weather generally expected through the long term period. && .AVIATION /00Z FRIDAY THROUGH TUESDAY/... High confidence in widespread cig restrictions throughout the 24 hr TAF forecast period. Cold air damming wedge conditions remain in place this evening with high pressure centered over the Mid-Atlantic ridging into the Carolinas. Low clouds will remain in place overnight possibly lowering to IFR/LIFR (already LIFR at DNL). Lower confidence in vsby forecast and going with prevailing VFR and tempo down to MVFR but they could drop earlier than forecast and stay down late tonight into mid morning Friday. Winds will be light from the northeast to east through the period. Some diurnal improvement is possible in cigs but confidence is low. Moisture will increase on Friday as a cold front begins to approach the area and some drizzle or light rain is expected to develop by mid afternoon after 20z from south to north with cigs falling again. EXTENDED AVIATION OUTLOOK...Periods of ceiling and visibility restrictions are possible through Saturday morning with deep moisture in place over the region. Very strong winds expected on Saturday behind the front. && .CAE WATCHES/WARNINGS/ADVISORIES... GA...Freeze Watch from Saturday evening through Sunday morning for GAZ040-063>065-077. SC...Freeze Watch from Saturday evening through Sunday morning for SCZ016-018-020>022-025>031-035-037-038-041-115-116- 135>137. && $$
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
929 PM CST Thu Mar 10 2022 .UPDATE... Issued at 929 PM CST Thu Mar 10 2022 Going forecast is in good shape and no changes planned this evening. The ~150 mile wide band of frontogenetically driven light to moderate snow continues to blanket all but the far northwest CWA with light to moderate snow. The band should continue to shift slowly southeast tonight, with snow tapering off to flurries before ending from the northwest. Its only been the past hour or two that we`ve really seen road conditions deteoriorating as residual pavement warmth took some time to be overcome. Forecast snowfall amounts look on target with 1-3" likely, mainly southeast of the I-55 corridor. - Izzi && .SHORT TERM... Issued at 253 PM CST Thu Mar 10 2022 Through Friday night... The going forecast message for tonight`s minor snow event remains on track. Did move forward the onset time of the steadier snow and inch up the snowfall amounts a smidge. While temporary heavier rates -- or at least more than "light" -- are expected, impacts still look to be on the minor end of the scale, helped by filtered sunshine earlier this afternoon warming pavement surfaces. So we continue to opt with just a Special Weather Statement (SPS) and associated other graphical messaging. The 100-120 kt upper jet has expanded over the area this afternoon, with associated broader synoptic scale forcing for ascent translating overhead. A lead impulse within this flow, as well as a tightening lower- to mid-level baroclinic zone, has resulted in a focused area of snow from southeast Iowa into western Illinois that is moving into north central Illinois as of 230 PM. There is analyzed frontogenesis (f-gen) within the 850 to 700 mb layer correlating with this area, and southerly flow and WAA at that layer to its south to help sustain this f-gen and moisture transport into this area. There also is some slightly negative or near negative values of saturated EPV (instability). While there is near-surface dry air as evidenced by dew points in the upper single digits to lower teens, observations and webcams are starting to show some non-accumulating snow occurring. With pavement temperatures in the 40s thanks to the earlier filtered sunshine. this will likely continue to be the case through the daytime hours on paved surfaces. Short term models such as the RAP sustain the mid-level f-gen zone of forcing eastward into the CWA through mid-evening. In particular, LaSalle, Livingston, Grundy, Will, and Kankakee Counties, where there is indication of half inch per hour rates at times through mid evening. The f-gen gradually focuses more east- southeast in the CWA later this evening into overnight, with a tapering from northwest to southeast as the mid-level trough gradually passes late tonight into Friday morning. Lingering light accumulating snow may be continuing through much of Friday morning east of I-57. Immediately on the heels of this system, and part effects from it, will be a modified arctic front diving southeastward into the region Friday afternoon. Guidance is in good agreement on the timing of this during the afternoon with temperatures dropping behind this into evening. Along the strengthening front itself, there is focused convergence and steepened low-level lapse rates. Forecast positive CAPE values are 10-30 J/kg on the RAP with the cloud layer intersecting the DGZ. This cloud layer is fairly shallow though, and the focus is moving quickly. It`s possible some gusty snow showers develop with this setup, especially in southern Wisconsin ahead of the vorticity maximum center. Did add some low PoPs for this Friday afternoon. As the cold air floods in, temperatures will drop into the single digits to lower teens by early Saturday morning. Wind chills by Friday mid-evening will be nearing zero, and by early Saturday morning will have dropped to 0 to 10 below, which is impressive for March 12. Lake effect clouds and likely at least flurries or light snow showers are expected into Porter County Friday night, especially late. Some minor accumulation may occur with these. MTF && .LONG TERM... Issued at 301 PM CST Thu Mar 10 2022 Saturday through Thursday... Main highlights remain the same for the long term: -Frigid air mass and below zero wind chills overnight Friday into Saturday. -Lake effect snow accumulations in Porter Co., IN Saturday morning ending during the afternoon. -Warm up coming at the end of the weekend into the workweek. By 00z Saturday, the main axis of an upper level trough will begin to depart east of the Great Lakes, sending a strong sfc cold front and - 20 to -22C 850mb temps down the fetch of Lake Michigan. Bufkit profiles at Burns Harbor, IN are advertising lake surface to 850mb delta Ts around 22C, 8-9k ft ELs, and 500-600 J/kg of lake-induced CAPE in the early morning hours on Saturday. CAMs are depicting convergence bands forming east of Porter county. As mentioned recently, limited moisture advection within the cold air mass could limit accumulations. The LES threat ends come the afternoon as low level winds back and snow pushes eastward out of the county. The main story for Saturday will be the subzero wind chills to start the day, and afternoon wind chills only in the teens. Actual highs will top out in the mid 20s. The surface high will slide southeast by Saturday night and a clipper moving through the Canadian Prairie into the Upper Great Lakes will place Illinois within warm return flow. Some guidance is hinting that northern Illinois could be on the far southern end of snow showers resulting from moderate mid level warm air advection Saturday night. Previous forecast decision was to keep PoPs dry but the latest update introduces some slight chances of snow and maybe just a dusting of accumulation for far northeast Illinois during the overnight hours. After a cold Saturday, warmer weather quickly returns. Sunday high temps will push into the mid 50s behind the surface warm front with gusty winds veering out of the west. Overall the warming trend next week looks solid. NBM daytime highs hold steadily in the mid to upper 50s, making a run towards mid 60s by next Thursday. The exception would be near the lake on Tuesday where onshore flow will keep temperatures in the mid 40s. But then another weak wave moving into the High Plains will again bring southerly flow areawide Wednesday into Thursday, keeping conditions warmer than normal, consistent with the CPC 6-10 day guidance, which has confidence in above normal temperature throughout the Midwest. As for precip trends, an upper level trough will make its way across the Midwest on Monday, pushing a weak cold front and northerly wind shift through the evening. Moisture looks fairly starved, therefore confidence on seeing measurable precipitation from this event is low. BW/Lenning && .AVIATION... For the 00Z TAFs... Forecast concerns for the terminals... *Snow tonight with reduced visibilities and MVFR ceilings *Winds turning westerly early Friday morning and increasing in speed Friday afternoon *VFR ceilings return Friday morning MVFR ceilings and snow have continued to move into the terminals this evening with reduced visibilities under 2 SM for most of the area. Lower visibilities under a mile have also been observed briefly as heavier bands of snow have moved overhead. The snow and reduced visibilities will continue into the predawn hours of Friday morning before drier air moves in aloft and brings the snowfall to an end. Total snowfall accumulations of 1 to 2 inches is expected at the Chicago terminals with slightly higher amounts possible at GYY. The MVFR ceilings will gradually lift after the snow comes to an end early Friday morning with VFR conditions prevailing through the rest of the day on Friday. Guidance does suggest that a few snow showers/flurries could be possible as the frontal boundary moves through late Friday afternoon, but confidence is not high enough to include formal mention in the TAFs at this time. The northeasterly winds will persist through the evening before tuning westerly after midnight with light speeds around 5 kts. Winds will begin to increase in speed Friday morning as the atmosphere becomes better mixed and begins to pull 20 to 25 kt gusts down to the surface. These breezy conditions will persist through the end of the TAF period with winds shifting northwesterly Friday evening as a frontal boundary pushes through the area. Yack && .LOT WATCHES/WARNINGS/ADVISORIES... IL...None. IN...None. LM...Small Craft Advisory...LMZ740-LMZ741-LMZ742...noon Friday to noon Saturday. Small Craft Advisory...LMZ743-LMZ744-LMZ745...3 PM Friday to 9 PM Saturday. && $$ Visit us at Follow us on Facebook, Twitter, and YouTube at:
Area Forecast Discussion
National Weather Service Melbourne FL
830 PM EST Thu Mar 10 2022 .UPDATE... ...Strong to Severe Storms Possible The Next Two Days... ...Turning Much Colder Saturday Night Behind a Strong Front... Current...Several late afternoon/early evening updates to adjust the earlier Severe Thunderstorm Watch and to adjust POPs/Temps as widespread convection along a larger scale outflow boundary dropped south across the CWA. The boundary now lies across the Martin County, and will drop south of the CWA by the top of the hour, and exit the far southern waters by about 10 PM. Evening update will remove POPs for the remainder of the night, except for a small shower/sprinkle threat across the far north toward sunrise. Both the HRRR and MAV/LAV MOS are more enthused about low clouds/fog across the north and central tonight. Given the combination of widespread rain (heavy across many areas, the rain-cooled air mass in place, and light winds, this seems fairly reasonable, and as such fog has been added to the grids/ZFP. && .AVIATION...00Z package also hit fog/stratus harder from MLB north from 09Z-13Z. Heavier rain did fall near the VRB-SUA corridor, so may need some AMDs down that was as well. For Fri, slightly lower POPs, and thus confidence in needing TEMPO TS across the northern aerodromes is a little lower. If so, best chance would be LEE-DAB, possibly SFB. But for now, went with VCTS ISM-MCO-TIX northward and left it out for MLB-SUA. && .MARINE...Passage of large scale convective outflow boundary and associated storms has made for rather chaotic winds, which shifted form south to north, and are now in the process of veering back around to E-SE. We should see these eventually veer back southerly after midnight, with speeds decreasing below 15kt. Seas 3-4ft. && Cristaldi/Rodriguez && .PREV DISCUSSION... (Issued 355 PM EST Thu Mar 10 2022) Friday...Stalled frontal boundary lingers north of the area, and may shift slightly northward as a warm front. Passing disturbances and lingering moisture will continue an unsettled pattern, with scattered showers and storms developing into the afternoon across north central FL and toward the east coast. PoPs range from 50-60 percent north of Orlando and 30-40 percent from around Orlando area southward through much of the Treasure Coast. Strong to isolated severe storms will continue to be possible with any convection that develops. Highs will continue to reach the 80s and possibly around 90 degrees across southern portions of the interior. Saturday-Sat Night...Unsettled and disturbed weather will continue into Saturday, which looks to be the most active day this week. A deep mid level low and associated trough will dig across the Great Lakes region and down the Mississippi Valley late Friday night, dragging a very strong cold front towards the FL peninsula. By 7am, models are in good agreement with the line of thunderstorms ahead of the front positioned across the FL Panhandle, with the line reaching the doorstep of Lake and Volusia counties by late morning to midday. This is a few hours slower than previously advertised, but the forecast will continue to be refined in terms of timing once confidence increases. With a slower arrival time, the front will take a bit longer to sweep through the area, with models reflecting a position over the Treasure Coast just prior to sunset. The threat for severe weather associated with this line continues to increase, with SPC maintaining a "Slight Risk" across most of the east central FL area on Saturday, with the Treasure Coast and Okeechobee County covered under a "Marginal Risk". So far, instability and forcing appears to be the greatest during the morning hours, depleting through the afternoon, so timing of the line becomes increasingly important if storms can tap into peak ingredients. A potent wind field at the surface into the mid levels could lead to damaging wind gusts of 60 mph, with a bit of low level shear aiding in the development of a brief tornado or two, especially for areas along and north of I-4, although severe weather will be possible across the entire area as the front passes. Temps at 500mb not incredibly impressive, so hail will not be as great of a threat but still could be present with growth of storm tops. As mentioned, there still lies quite a bit of uncertainty with the evolution of the event on Saturday, mainly stemming from timing of the frontal passage, but all of east central FL should be prepared for strong to severe thunderstorms capable of producing damaging winds, hail, and brief tornadoes. For now, will clear most rain chances from the forecast after sunset, but a few lingering showers and storms could persist across the Treasure Coast if the line lags according to model trends. Behind the front, breezy southwest winds will veer quickly to the west northwest, maintaining speeds of 15-20 mph into the late afternoon and early evening hours. Highs on Saturday will reach the mid to upper 70s across the north and climb to the low to mid 80s south of Orlando. Dry air will move in rapidly behind the front, dropping PW values to a measly 0.10", hence the zero rain chances after 8pm Saturday night. Dewpoints will fall, and with much cooler air arriving alongside the dryness, temperatures will also fall well below normal values. Coldest locations will be across northern Lake and Volusia counties which will drop to 34-35F, then warming a few degrees progressing southward, to 38-40 from Osceola to coastal Volusia and the low/mid 40s for the Space Coast and Okeechobee County and the upper 40s/low 50s along the Treasure Coast. Northwest winds will remain above 10 mph overnight, which will lead to wind chill readings in the upper 20s/low 30s in coldest locations and the mid 30s elsewhere. Extended...(previous) The chilly post frontal cooldown Sunday wl be somewhat short-lived as temperatures slowly moderate early in the week. Dry and cool Sunday with highs in the 60s to be followed by lows in the 40s to around 50 degrees Sunday night, as onshore winds begin to develop. By Mon aftn a small chc of showers return to the marine area with further moderation of temps in continuing onshore flow conditions. Another approaching Gulf system is advertised around Tue and rain chcs have consequently been bumped up to sct coverage Tue into Wed at this early juncture. Highs will reach well into the 70s to L80s by Tue into Wed. && .MARINE... Friday-Friday night...After diminishing overnight, south winds increase back to 15-20 knots, with seas 3-4 feet. Showers/storms expected to be confined to the northern waters much of the day. Saturday...Hazardous marine conditions will arrive this weekend as a strong cold front sweeps across the Atlantic waters on Saturday. Prior to the front`s arrival, the pressure gradient will significantly tighten, increasing south to southwest winds late Friday to near 20 knots, further increasing to 25-30 knots by Saturday afternoon. Winds will begin to veer west and then northwesterly towards the evening as the front moves through late in the day. A line of strong to severe thunderstorms is forecast to push ahead of the boundary, bringing damaging wind gusts, frequent lightning, locally higher seas and waterspouts across the Atlantic waters late Sat morning through the late afternoon. Seas will build from 4-6 ft in the morning to 8-11 ft overnight. At least SCA headlines will be necessary this weekend, with possible gale force conditions. Sunday-Monday...Marine conditions will remain hazardous early next week as the front pulls away and high pressure builds over the southeast US. North winds veer northeast on Sunday diminishing below 20 knots by the afternoon as seas slowly fall from 8-11 ft in the Gulf Stream to 5-9 ft. Conditions will continue to improve into Monday but still remain poor, with east winds 15-20 knots and seas 4- 6 ft. && .PRELIMINARY POINT TEMPS/POPS... DAB 64 82 66 77 / 30 60 30 90 MCO 67 89 69 80 / 30 40 20 90 MLB 66 86 70 83 / 40 40 20 90 VRB 65 87 69 84 / 40 40 20 80 LEE 67 85 69 77 / 30 50 20 90 SFB 66 86 68 79 / 30 50 20 90 ORL 68 88 70 80 / 30 50 20 90 FPR 65 86 69 85 / 40 30 10 80 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...None. AM...None. && $$
Area Forecast Discussion
National Weather Service Phoenix AZ
517 PM MST Thu Mar 10 2022 .UPDATE...Updated 00Z Aviation Discussion. .SYNOPSIS... A mostly dry weather system will move through the region from this afternoon to tonight bringing windy conditions to the area, especially across southeast California and southwest Arizona where blowing dust is a concern. Isolated to scattered light showers should also accompany this system, although with the better chances across the high country north and east of Phoenix. Dry conditions under mostly clear skies will then prevail into the weekend through the first half of next week with high temperatures climbing back well into the eighties by early next week. && .DISCUSSION... The upper air analysis features a long positively tilted short-wave trough axis with PVA anomalies extending from the Great Basin and dropping into S CA, with strong zonal flow across our area just ahead of the system. The WV image shows the main enhanced moisture plume of the system to the NE ejecting through the S Rockies. This also coincided with areas of light precip returns on early afternoon radar across the N half of AZ. The IR satellite imagery shows the large cloud shield of the system collocated with the systems main moisture plume to the NE of the area with clear to partly cloudy skies lingering over our area. Visible and other satellite imagery also showed some blowing dust channels beginning to appear in E Riverside cnty crossing I-10. The dryish shortwave weather system drops through the region from this afternoon and well into tonight, with a strong surface high pressure area building to the north. The tightening gradient has already begun to generate very strong, gusty northerly wind conditions in parts of SE CA and SW AZ. With max advisory level forecast wind gusts of 40-50 mph with, and behind the cold front, the threat of blowing dust will continue to be very likely in those areas through this evening. The advisories also includes JTNP and the Lower CO River Valley. In addition, very breezy conditions will also spread east into Phoenix and the lower deserts from this afternoon and evening into tonight, with the higher gusts up to 25- 35 mph in these areas. The chances of modest amounts of isolated-scattered light rain and showers across Phoenix and over the high terrain this evening and tonight have decreased a bit since yesterday. This still includes some light snow over our high terrain east of Phoenix above ~5-6 Kft. The NBM and ensembles now favor <0.03" of rain for the Phoenix Metro area and <0.5" of snow for the highest elevations to the east. The favored NBM POPs/PPIs have now lowered to a fleeting 9-30% after 00Z Fri (Thu evening) for the greater Phoenix area, and 30-40% for the eastern high terrain near Globe for this evening and tonight. A very small amount of MU/SBCAPE is still in the mix as models and NBM hold on to the non-zero, <5% chances for isolated evening thunderstorms and convection. The Grand Ensemble and NBM are in good agreement on sufficient cold air with this system to keep temperatures in a fairly limited range through tomorrow as the system ejects east. They are also in very good agreement on a warm-up starting this weekend into early next week as a strong high pressure anomaly builds in by Sat across the W CONUS. After a temporary flattening of the ridge on Sun, ensembles also favor reinforcing high pressure on Mon-Tue with highs punching well into the 80s early next week. Currently the warmest day is still forecast for Tue with highs in the mid-upper 80s. The NBM probability of a high of at least 90 degrees for next Tuesday has fallen to 42% today, down from 52% yesterday. && .AVIATION...Updated at 0017Z. South-Central Arizona including KPHX, KIWA, KSDL, and KDVT: Current gusty westerly winds will continue to increase through the early evening as a cold front pushes through the region. Gusts will generally remain between 20-30 kts but a few brief gusts around 35 kts can`t be ruled out. The HRRR now shows ~45% chance of gusts reaching or exceeding 30 kts this evening. Some areas of blowing dust could potentially impact slantwise visibilities and potentially surface visibilities, though they should remain above 5-6SM. Gusts will weaken and taper off going through the latter part of the evening after FROPA. Could see some LLWS issues at some of the terminals, but expect this to remain below TAF thresholds. Westerly winds are expected to continue through most of tonight, then turn northeasterly towards morning. These northeasterly winds (8-10kts with gusts as high as 15 kts) are then expected top continue into the mid-late afternoon hours before becoming more typical westerly during the late afternoon/early evening hours on Friday. A return to more familiar diurnal easterly winds is then anticipated by late evening on Friday. Aside from the winds, rain chances are low (< 20%) with the best chances favored to remain over the high terrain north and east of the metro today. If any virga/light showers do develop near the terminals, expect little to no rainfall to reach the ground with gusty erratic winds possible. FEW-SCT clouds aoa 7-9 kft will continue through the evening before drier air pushes in during the overnight hours and promotes clear skies. Southeast California/Southwest Arizona including KIPL and KBLH: Current very strong gusty winds across the region are expected to persist well into the evening hours before diminishing around/shortly after midnight. Northerly gusts could reach as high as 35-45 kts at KBLH this evening while winds at KIPL are expected to be weaker. As a result of the strong winds, areas of blowing dust will be possible, particularly near KBLH, which may drop visibilities down to around 1 SM at times, and create slant-range visibility issues as well. WInds are expected to continue to gradually subside late tonight/Friday at KIPL. Winds will likely increase for a time again at KBLH during the early/mid-morning hours on Friday as northerly winds aloft increase, with LLWS concerns also becoming a possibility, before winds finally subsiding for good during the late morning/afternoon hours on Friday. Otherwise, FEW clouds will remain aoa 9 kft during the period. && .FIRE WEATHER... Saturday through Wednesday: High pressure will strengthen over the region into early next week leading to a strong warming trend and continued dry conditions. High temperatures will warm from near normal on Saturday to 9-12 degrees above normal by Tuesday. Winds through the bulk of the period will be fairly light, but some breeziness is likely on Sunday and Wednesday. Low humidities will prevail each day with minimum readings mostly between 7-12% each day, while overnight readings generally only recover to between 20-40%. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...Blowing Dust Advisory until 2 AM MST Friday for AZZ530-531-533. Wind Advisory until 2 AM MST Friday for AZZ530-531-533. Blowing Dust Advisory until 10 PM MST this evening for AZZ532. Wind Advisory until 10 PM MST this evening for AZZ532. CA...Wind Advisory until 10 PM PST this evening for CAZ560-561-568. Blowing Dust Advisory until 1 AM PST Friday for CAZ564-569-570. Wind Advisory until 1 AM PST Friday for CAZ564-569-570. Blowing Dust Advisory until 10 PM PST this evening for CAZ561- 568. Blowing Dust Advisory until 9 PM PST this evening for CAZ563-565- 567. Wind Advisory until 9 PM PST this evening for CAZ563-565-567. && $$ Visit us on Facebook, Twitter, and at DISCUSSION...Sawtelle AVIATION...Percha/Smith FIRE WEATHER...Kuhlman
National Weather Service Raleigh NC
932 PM EST Thu Mar 10 2022 .SYNOPSIS... A wedge of cooler air will remain across North Carolina tonight into Friday. A strong cold front will then cross the region late Friday night and early Saturday. High pressure will then build into the region for the end of the weekend, resulting in colder and drier weather Sunday and Monday. && .NEAR TERM /THROUGH FRIDAY/... As of 930 PM Thursday... Aside from some lingering spotty light drizzle over the Coastal Plain, the rest of the night should largely be dry. Low clouds have lifted/scattered over the northern Piedmont, generally along and north of I-85. Although high clouds remain, this decrease in cloud coverage, combined with winds becoming calm as the surface high sits over the southern mid-Atlantic through tonight. The last few runs of the HRRR show fog developing over the northern Piedmont late tonight and lingering through early Friday morning. Should the fog develop, it could become dense. Elsewhere, low clouds will persist through tonight. As for temperatures, where the low clouds have scattered out and if the high clouds break apart, the temperature could drop into the mid 30s, otherwise elsewhere upper 30s to low 40s are expected. -KC Friday will be a difficult forecast as guidance is inconsistent on how quickly to erode the CAD leading to a 10 to 15 degree spread in high temperatures. The NAM is more persistent with keeping the CAD wedge in place through a majority of the day on Friday, while GFS/ECMWF quickly erode the wedge Friday morning and raise temperatures well into the mid/upper 60s. Since the NAM is usually superior with CAD, this forecast package will err on the side of cooler guidance. However, temperatures Friday could be even cooler than the current forecast if this solution verifies. Showers will start to move in from SC as deep WAA begin to overspread the area ahead of the approaching cold front. -Swiggett && .SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY/... As of 330 PM Thursday... While showers will increase from the south Friday evening as the wedge boundary moves north, rain chances will dramatically rise as a cold front approaches from the west. A wave of low pressure will be somewhere along the front across north-central North Carolina around sunrise Saturday, and that has resulted in an uptick for the amount of precipitation forecast in the Triad late Friday night. Rainfall amounts are expected to be around an inch areawide. Have slightly expanded the chance for thunder, now covering all but the northwesternmost portions of the forecast area. While much of the forecast area is under a marginal risk for severe weather Friday night, particularly after midnight, a low-level inversion will limit the amount of available instability for thunderstorms and should limit the overall severe weather threat. However, SPC has issued a slight risk for severe thunderstorms generally east of the US-1 corridor for Saturday, and the addition of some surface-based instability after sunrise should allow for a greater threat of severe weather during the daytime hours. There will be some modest speed and directional wind shear in the low levels as well. Temperatures will follow a non-diurnal cycle, with temperatures remaining steady or slowly rising Friday night. On Saturday, temperatures will fall through the day in the west, while remaining nearly steady in the east during the morning then falling through the afternoon. It appears that precipitation will move east before colder air arrives, but a rogue snowflake cannot be ruled out as precipitation comes to an end. That being said, it has been several days since temperatures were below freezing, so no snowfall accumulation is expected. Finally, wind will increase in advance of the cold front, with gusts up to 20-25 mph overnight and widespread gusts of 30-40 mph behind the cold front Saturday afternoon. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... As of 330 PM Thursday... The strong cold front Saturday night moves offshore into the western Atlantic into Sunday morning as the mid-level trough tracks into the north-central Atlantic. Behind it, a 1032 mb cold high pressure settles across the deep south. Immediately behind the front, a tight pressure gradient will remain, with the departing low pressure system tied to the cold front and high pressure over northern MS. In addition to the tight pressure gradient, strong low-level 925 mb winds of 30-35 kts with the cold air advection will result in rather gusty northwest winds between 30-40 mph, especially in the early to late evening hours. With temperatures tumbling to a hard freeze into the upper teens to lower 20s for overnight lows (15-20 degrees below normal), wind chills will be in the low to upper teens, making for a much colder night that what has been experienced lately. Although we have not reached the peak growing season, it might be a good idea to bring in potted plants. As high pressure settles across the deep south early Sunday, winds should decrease toward sunrise Sunday. Weak mid-level ridging will start to develop on Sunday afternoon and the surface high will shift toward the southeast coast of NC by evening. With the cold airmass in place, highs will remain 10- 12 degrees below average in the upper 40s to lower 50s. Mon-Thu: A gradual warming trend will take place during this period, as high pressure off the coast of NC shifts east toward Bermuda. Highs will be some 5-10 degrees above normal in the low to middle 60s Monday to the upper 60s to lower 70s Tue-Thu. Aloft, ridging will be in place through Monday. The subtropical jet will be active in the Tue-Thu period. With the southern stream jet, a mid-level trough is forecast to track from Colorado Sunday night into TX/OK by Tuesday and become closed off from the main flow. There remains some uncertainty in the timing and track of this closed mid-level system. The GFS and NAEFS are faster, bringing the system across the area Wed-early Thursday, while the ECMWF/CMC and the previous Euro ensemble are slower, bringing the system in Wednesday night to late Thursday night. Have kept low-end PoPs late Tue and Wed, then chance PoPs on Thursday. && .AVIATION /00Z FRIDAY THROUGH TUESDAY/... As of 700 PM Thursday... 24 hour TAF period: Fairly confident sub-VFR conditions will persist and/or develop this evening and tonight. Of lower confidence is how low the visbys will get and how expansive they will be. There is a strong signal for fog to develop near the VA/NC border and spread south and southeastward over KGSO, KINT and KRDU after midnight. Where the lower cigs (MVFR/IFR) hold on (KFAY and KRWI) the visbys may not drop as low, but conditions will be sub-VFR nonetheless. Winds should become calm to light and variable through tonight. Sub- VFR conditions may linger through much of the morning, gradually improving back to VFR late Friday morning into Friday afternoon. Winds should become southerly at 5-10 kts Friday afternoon. -KC Looking ahead: A strong cold front will bring restrictions in showers and isolated thunderstorms Friday night into Saturday morning. While showers and restrictions will come to an end Saturday afternoon, strong winds are expected out of the south Friday night and veering to the west Saturday with winds up to 40 mph. Winds will settle down Saturday night, and dry weather is expected Sunday and Monday before a slight chance of rain returns on Tuesday. -Green && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Green NEAR TERM...KC/Swiggett SHORT TERM...Green LONG TERM...Kren AVIATION...KC/Green