Marine Weather and Tide Forecast for Nevada, IA
March 18, 2024 11:54 PM CDT (04:54 UTC) Change Location
Sunrise 7:18 AM Sunset 7:26 PM Moonrise 11:51 AM Moonset 3:19 AM |
Area Discussion for - Des Moines, IA
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FXUS63 KDMX 190452 AFDDMX
Area Forecast Discussion National Weather Service Des Moines IA 1152 PM CDT Mon Mar 18 2024
Updated for the 06z Aviation Discussion
KEY MESSAGES
- Elevated fire weather concerns Tuesday and Wednesday, possibly continuing into Thursday.
- Chances for rain/snow late Thursday into Thursday night.
Highest chances for light snow accumulations in far northern Iowa.
- High chances for rain/snow late in the weekend into early next week. Considerable uncertainty with potential snowfall amounts at this time.
DISCUSSION
Issued at 241 PM CDT Mon Mar 18 2024
Stratus deck that dropped south into the state overnight has steadily eroded over the last few hours. The sunshine has helped put forecast highs back on track, although still running 10 to 15 degrees below average for mid March and feels quite chilly when combined with the blustery northwest wind. Winds tail off a bit and become more westerly this evening into tonight as a sfc ridge axis passes through. Winds on the backside of the ridge ramp back up quickly and should be gusty out of the northwest again by morning. Switch to a warm air advection regime will push afternoon temps back into the 50s and 60s. Fire weather concerns crop up as both wind speeds and min RH values will not be far removed from critical thresholds. NBM RH is marginally improved compared to today, however the output running near or above most bias corrected guidance which may better capture the recent general trend of overly moist dewpoint guidance.
Upper pattern energy really picks up toward the end of the week as a deep low is carved out over the eastern two-thirds of Canada. A low amplitude but robust shortwave rounds the base of the upper low and pushes through the region Thursday night, akin to a traditional 'clipper' type system. Bulk of the QPF tied to this wave is focused on an intense mid-level fgen zone sweeping south across the Dakotas and into southern Minnesota. This band may clip our far northern counties with the NBM advertising a 20-30% chance for 1" of snowfall. Further south, precip potential is limited by weaker forcing and delayed moisture return. Models activate a strong surface front crashing through the state late Thursday night into Friday morning and provides a brief opportunity for more widespread precip. Model soundings suggest temp profiles will still be warm enough to support mostly rain from about Hwy 30, but wintry/mixed ptypes could be in play for points northward.
Attention then turns to the weekend into early next week when most of the model guidance spectrum advertises increasing potential for a prolonged period of precip over the region. Phased kinematic and particularly strong thermodynamic forcing contributions ahead of a wave diving south of Canada will set the stage for precip development Saturday night and into Sunday. Deep synoptic lift continues into Sunday night and Monday as an upper low emerges from the western CONUS. Ensemble output shows remarkable agreement wrt QPF at that time range with both GEFS/ECENS camps posting 80%+ probs of 1" by 00z Tuesday. Where stark differences arise is within the low-level thermal fields between the two models and the fallout on ptypes through the event. Euro is much warmer at the onset with 850mb 0c isotherm north toward I-90. The GFS is much more aggressive with the colder air and slower to pull the warm sector back northward, which favors wintry ptypes for the initial wave of precipitation. Euro is more delayed with the arrival of cold air until northerly winds push it south on the backside of the departing low late Monday into Tuesday. At this same time, the GFS is much more progressive and already drying out the area.
Not surprisingly, ensemble data sets show a massive range in potential snowfall amounts which considerably hampers forecaster confidence at this point in time. The possible scenarios are likely to change and evolve over the coming days, so those with travel interests early next week will want to pay attention for forecast updates in the near future.
AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/
Issued at 1129 PM CDT Mon Mar 18 2024
Primary concerns within the TAF period continue to revolve around winds, both at the surface and aloft. LLWS mentions continue across the TAF sites, generally within the 06z to 14z window, as winds aloft turn NW and strong prior to surface winds doing similar. As just mentioned, surface winds will turn NW across the area by mid-morning, including gusts into the 20s kts at all sites. Strongest winds remain expected in/around KMCW/KALO where gusts to/in excess of 30 kts are likely.
Otherwise, VFR conditions will prevail.
DMX WATCHES/WARNINGS/ADVISORIES
None.
Area Forecast Discussion National Weather Service Des Moines IA 1152 PM CDT Mon Mar 18 2024
Updated for the 06z Aviation Discussion
KEY MESSAGES
- Elevated fire weather concerns Tuesday and Wednesday, possibly continuing into Thursday.
- Chances for rain/snow late Thursday into Thursday night.
Highest chances for light snow accumulations in far northern Iowa.
- High chances for rain/snow late in the weekend into early next week. Considerable uncertainty with potential snowfall amounts at this time.
DISCUSSION
Issued at 241 PM CDT Mon Mar 18 2024
Stratus deck that dropped south into the state overnight has steadily eroded over the last few hours. The sunshine has helped put forecast highs back on track, although still running 10 to 15 degrees below average for mid March and feels quite chilly when combined with the blustery northwest wind. Winds tail off a bit and become more westerly this evening into tonight as a sfc ridge axis passes through. Winds on the backside of the ridge ramp back up quickly and should be gusty out of the northwest again by morning. Switch to a warm air advection regime will push afternoon temps back into the 50s and 60s. Fire weather concerns crop up as both wind speeds and min RH values will not be far removed from critical thresholds. NBM RH is marginally improved compared to today, however the output running near or above most bias corrected guidance which may better capture the recent general trend of overly moist dewpoint guidance.
Upper pattern energy really picks up toward the end of the week as a deep low is carved out over the eastern two-thirds of Canada. A low amplitude but robust shortwave rounds the base of the upper low and pushes through the region Thursday night, akin to a traditional 'clipper' type system. Bulk of the QPF tied to this wave is focused on an intense mid-level fgen zone sweeping south across the Dakotas and into southern Minnesota. This band may clip our far northern counties with the NBM advertising a 20-30% chance for 1" of snowfall. Further south, precip potential is limited by weaker forcing and delayed moisture return. Models activate a strong surface front crashing through the state late Thursday night into Friday morning and provides a brief opportunity for more widespread precip. Model soundings suggest temp profiles will still be warm enough to support mostly rain from about Hwy 30, but wintry/mixed ptypes could be in play for points northward.
Attention then turns to the weekend into early next week when most of the model guidance spectrum advertises increasing potential for a prolonged period of precip over the region. Phased kinematic and particularly strong thermodynamic forcing contributions ahead of a wave diving south of Canada will set the stage for precip development Saturday night and into Sunday. Deep synoptic lift continues into Sunday night and Monday as an upper low emerges from the western CONUS. Ensemble output shows remarkable agreement wrt QPF at that time range with both GEFS/ECENS camps posting 80%+ probs of 1" by 00z Tuesday. Where stark differences arise is within the low-level thermal fields between the two models and the fallout on ptypes through the event. Euro is much warmer at the onset with 850mb 0c isotherm north toward I-90. The GFS is much more aggressive with the colder air and slower to pull the warm sector back northward, which favors wintry ptypes for the initial wave of precipitation. Euro is more delayed with the arrival of cold air until northerly winds push it south on the backside of the departing low late Monday into Tuesday. At this same time, the GFS is much more progressive and already drying out the area.
Not surprisingly, ensemble data sets show a massive range in potential snowfall amounts which considerably hampers forecaster confidence at this point in time. The possible scenarios are likely to change and evolve over the coming days, so those with travel interests early next week will want to pay attention for forecast updates in the near future.
AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/
Issued at 1129 PM CDT Mon Mar 18 2024
Primary concerns within the TAF period continue to revolve around winds, both at the surface and aloft. LLWS mentions continue across the TAF sites, generally within the 06z to 14z window, as winds aloft turn NW and strong prior to surface winds doing similar. As just mentioned, surface winds will turn NW across the area by mid-morning, including gusts into the 20s kts at all sites. Strongest winds remain expected in/around KMCW/KALO where gusts to/in excess of 30 kts are likely.
Otherwise, VFR conditions will prevail.
DMX WATCHES/WARNINGS/ADVISORIES
None.
Airport Reports
EDIT (hide/show)  Help Click EDIT to display multiple airports. Follow links for more data.Airport | Dist | Age | Wind kt | Vis | Sky | Weather | Temp | DewPt | RH | inHg |
KAMW AMES MUNI,IA | 9 sm | 61 min | SSW 09 | 10 sm | Clear | 28°F | 12°F | 50% | 30.05 | |
KBNW BOONE MUNI,IA | 21 sm | 19 min | SW 11G16 | 10 sm | Clear | 30°F | 10°F | 43% | 30.00 | |
KIKV ANKENY RGNL,IA | 24 sm | 19 min | SW 07 | 10 sm | Clear | 32°F | 10°F | 40% | 30.06 |
Des Moines, IA,
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