Marine Weather and Tides
3/30/2021 -- ANZ330 has been split into ANZ331 and ANZ332. Click EDIT in Marine Forecast and select your new zone.
1/26/2021 -- The West Coast Satellite images havd been updated. They now use GEOS-17.
1/1/2021 -- The 7 day forecast are now working well. Thank you NOAA for your support.
|Sunrise 6:45AM||Sunset 7:09PM||Friday September 17, 2021 10:54 AM CDT (15:54 UTC)||Moonrise 4:54PM||Moonset 1:54AM||Illumination 84%|
7 Day Forecast for Marine Location Near Jonesburg, MOHourly EDIT Help
Area Discussion for - St. Louis, MO  (on/off)  Help NOTE: mouseover dotted underlined text for definition
FXUS63 KLSX 171117 AFDLSX
Area Forecast Discussion . Updated Aviation National Weather Service Saint Louis MO 617 AM CDT Fri Sep 17 2021
SHORT TERM. (Through Late Saturday Afternoon) Issued at 322 AM CDT Fri Sep 17 2021
Two areas of isolated showers and thunderstorms are possible this afternoon and early evening. The first includes portions of southeast Missouri and southwest Illinois where higher surface moisture resides and weak forcing for ascent occurs downstream of a shortwave trough. A second area where isolated storms are possible is in parts of northeast Missouri and west-central Illinois, mainly very late this afternoon into the early evening hours as a cold front approaches from the northwest. This front is forecast to wash out/dissipate by mid-late evening however. Loss of daytime instability is expected to yield dissipating showers/storms by late evening, with dry weather forecast for the remainder of the night areawide.
Shower and thunderstorm activity on Saturday looks to focus across parts of southeast Missouri and southwest Illinois once again near a mid/upper level shear axis. Slightly higher near-surface moisture and associated instability also should help focus activity in these regions. Further north, cannot totally rule out a stray shower or two, but weak cool/dry advection behind northeasterly surface winds suggests keeping forecast dry at this time.
Above normal temperatures are favored through the short-term forecast period. Highs this afternoon and on Saturday are forecast to range from the low to upper 80s. Coolest conditions are likely to be in southeast Missouri and southwest Illinois due to more copious cloud cover and shower/thunderstorm chances. At least a slight increase in cloud cover overnight tonight also should lead to milder temperatures compared to this morning. Look for lows to only drop back into the low to mid 60s. Climatologically speaking, temperatures over the next 36 hours will generally be about 5-10 degrees above normal day/night.
LONG TERM. (Saturday Night through Thursday) Issued at 322 AM CDT Fri Sep 17 2021
(Saturday Night - Monday)
There is likely to be little/no change in the synoptic pattern to end the weekend and start the following work week. A midlevel closed low is forecast to develop by early Sunday and eventually move northward up the Mississippi River Valley on Monday. This feature should help develop a chance of thunderstorms each day, mainly during the afternoon/early evening hours during peak heating. Areas favored for this activity based on the track/timing of the midlevel low include southeast Missouri and southern Illinois. Further northwest, dry weather is forecast to continue along with temperatures remaining about 5-10 degrees above normal for mid/late September.
(Monday Night - Thursday)
A big change in the upper air pattern across the CONUS begins to take shape Monday night as a strong trough (500-hPa heights 1-2 sigma below normal) traverses the northern Plains. The timing of this feature (and its associated cold front) has sped up gradually over the past 24-48 hours. The most likely time for the cold front to move through the bi-state area is now Monday night into early Tuesday. Differences still exist amongst GEFS/EPS members, with the deterministic GFS and most of its members on the faster end and the ECMWF/EPS a bit slower. However, as stated above, the overall trend has been for a faster passage of the mid/upper level trough axis and the associated frontal boundary through our neck of the woods.
Favorable moisture return ahead of this system, combined with strong mid/upper level forcing for ascent should yield a good chance for widespread rainfall across the area. Showers and thunderstorms are possible along the front, and due to the best mid/upper level forcing lagging the frontal passage, this front should have anafrontal characteristics. More specifically, widespread post- frontal rainfall looks like a pretty good bet at this point in time. We have some likely PoPs now on Tuesday for southern and eastern sections of the CWA, but as confidence in frontal timing increases, these PoPs likely will need to be raised across the entire CWA over a 6-12 hour period between Monday night and Tuesday.
While exact temperatures will heavily depend on specific timing of the cold front, the theme will be for much cooler values in its wake. The air mass is fairly strong for mid/late September, characterized by 850-hPa temperature anomalies of -4 to -8C and a +1-2 sigma surface anticyclone. Highs on Wednesday and Thursday are forecast to be mostly in the low to mid 70s, with lows Tuesday and Wednesday night in the upper 40s to low 50s. These values would be about 5-10 degrees below normal, and after the persistent warmth beforehand, it will definitely feel more like Fall. The possibility exists for one of Tuesday or Wednesday night to be several degrees cooler than forecast, if the timing of the surface ridge is favorable.
AVIATION. (For the 12z TAFs through 12z Saturday Morning) Issued at 614 AM CDT Fri Sep 17 2021
Fog is expected at KCPS and KSUS early this morning before dissipating. Isolated showers and thunderstorms are forecast this afternoon and early evening, but they are not expected to impact the terminals. Better chances of this activity exist in southeast Missouri and southwest Illinois and northeast Missouri respectively. Models are hinting at fog/stratus potentially late tonight into Saturday morning, but did not have confidence to introduce anything quite yet with this forecast.
LSX WATCHES/WARNINGS/ADVISORIES. MO . None. IL . None.
Weather Reporting StationsEDIT (on/off)  Help NOTE: Click on distance to see the station location on a map
Airport ReportsEDIT (on/off)  Help Click EDIT to display multiple airports. Follow links for more data.
|St. Louis, Spirit Of St. Louis Airport, MO||39 mi||61 min||N 0||7.00 mi||Fair||75°F||66°F||74%||1018.8 hPa|
Link to 5 minute data for KSUS
Wind History from SUS (wind in knots)
|1 day ago||E||NE||E||E||NE|
|2 days ago||SW|
EDIT Weekend mode (on/off) (on/off)  Help
EDIT (on/off)  Help
Weather Map(on/off)  Help Weather Map
GEOS Local Image of EDIT
NOTE: This section has been updated as of 1/26/2021. If the image you are expecting is not showing, please let me know. You may use the EDIT function to update your location.
Link to Loop
Other links: GEOS-West Contential US Full GOES-East
Please read website Cookie, Privacy, and Disclamers by clicking HERE.