TZUTC: 0000   
   MSGID: 168204.weather@1:2320/105 2dc02677   
   PID: Synchronet 3.21a-Linux master/123f2d28a Jul 12 2025 GCC 12.2.0   
   TID: SBBSecho 3.28-Linux master/123f2d28a Jul 12 2025 GCC 12.2.0   
   BBSID: CAPCITY2   
   CHRS: ASCII 1   
   FORMAT: flowed   
   FOUS30 KWBC 030014   
   QPFERD   
      
   Excessive Rainfall Discussion   
   NWS Weather Prediction Center College Park MD   
   714 PM EST Fri Jan 2 2026   
      
   Day 1   
   Valid 01Z Sat Jan 03 2026 - 12Z Sat Jan 03 2026   
      
   ...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FOR THE CENTRAL   
   CALIFORNIA COAST NORTHWARD INTO NORTHERN CALIFORNIA...   
      
   01Z Update...   
   The 18Z HREF guidance supports the idea that few changes...if=20   
   any...are needed to the Marginal Risk area for the central=20   
   California coast northward. The upper trough/front...shown by=20   
   satellite imagery to still be offshore this evening...has gotten=20   
   close enough to bring the first showers to northern California.=20   
   Increasing coverage of rainfall and an increase in rainfall rates=20   
   is expcted this evening and tonight as the trough/front continues=20   
   moving eastward. Some localized runoff issues will be possible=20   
   overnight and early Saturday morning given moderate to locally=20   
   heavy rainfall rates (isolated 0.50+"/hour) and the moist/wet=20   
   antecedent conditions.   
      
   Bann   
      
   0830Z Excessive Rainfall Discussion...   
      
   No major model disagreements with the eastward push of the strong   
   mid to upper level low off the northern California coast day 1. The   
   low level southerly flow will strengthen Friday along and ahead of   
   the associated frontal boundary pushing toward the central to   
   northern California coast. While PW values are only 1 to 1.5   
   standard deviations above the mean, the 850-700 mb moisture flux   
   values are more anomalous, 2-3+ standard deviations above the mean.   
   Precip should increase in intensity along the northern CA coast   
   after 0000 UTC Sat, and spread south into coastal central CA in the   
   0600-1200 UTC time frame. The frontal boundary is expected to be   
   fairly progressive, limiting very heavy rainfall totals. HREF and   
   RRFS neighborhood probabilities for .50"+ hourly amounts are   
   generally less than 30%, with a few localized 60%+ probabilities   
   along the central CA coast range to the south of Monterey, and   
   across the northern Sierra. Areal average 1 to 1.5" amounts   
   expected along the central to northern CA coast and 1.5-2" in the   
   northern Sierra with isolated heavier totals of 2.5-3"+ possible.   
   No significant changes made to the previous marginal risk, with   
   localized runoff issues possible where soils remain fairly   
   saturated from recent rains, especially across northern CA.   
      
   Oravec   
      
      
   Day 2   
   Valid 12Z Sat Jan 03 2026 - 12Z Sun Jan 04 2026   
      
   ...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF THE   
   NORTHERN SIERRA AND SOUTHERN CALIFORNIA...   
      
   19z Update: Only minor changes made with this update. The 12z high   
   res models continue to depict a band of heavy rainfall moving   
   southward across the Transverse Range between 12z Sat and 00z Sun.   
   Most high res members depict localized hourly rainfall upwards of   
   0.5"-1", which should be enough to result in isolated to scattered   
   flash flooding.   
      
   Chenard   
      
   ...Previous Discussion...   
      
   The axis of anomalous 850-700 mb moisture flux values...2 to 4   
   standard deviations above the mean...along and ahead of the inland   
   moving frontal boundary at the end of the day 1 period will impact   
   the upslope areas of the northern Sierra and spread through the   
   Transverse Ranges of Southern California day 2. The primary change   
   from the previous outlook was to add a small slight risk area in   
   the upslope area of the Northern Sierra. HREF neighborhood   
   probabilities for .50"+ hourly rainfall amounts are fairly   
   high...50%+ at the beginning of the day 2 period and again in the   
   2100 UTC Sat to 0000 UTC Sun period. This will result in day 2   
   rainfall totals of 2-4"+ in a region of fairly saturated soils from   
   recent heavy rains. No changes of note made to the previous slight   
   risk area over Southern CA in the vicinity of the Transverse   
   Range. The south southwesterly low level flow will have a   
   significant upslope component into the Transverse Ranges during   
   the first half of day 2. This is reflected in both the HREF and   
   RRFS .50"+ hourly probabilities which are high, 50-80%+ during this   
   period. Localized runoff issues are possible where soils remain   
   fairly saturated from recent heavy rains.   
      
   Oravec   
      
      
   Day 3   
   Valid 12Z Sun Jan 04 2026 - 12Z Mon Jan 05 2026   
      
   ...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ALONG THE   
   CALIFORNIA COAST AND IN THE UPSLOPE OF THE SIERRA...   
      
   19z Update: Minimal changes needed to the inherited Marginal risk.   
   Gave some consideration to carrying over the the day 2 Northern   
   Sierra Slight risk into day 3 as periods of heavy rainfall will   
   continue into Sunday. However, snow levels will drop a bit and   
   thus at this point any Slight risk area would probably be too   
   narrow to depict. Either way, some flood impacts are likely to   
   continue into Sunday across the Marginal risk area.   
      
   Chenard   
      
      
   ...Previous Discussion...   
      
   Additional shortwave energy expected to rotate through the mean   
   trof position along the West coast and inland across California day   
   3. This will support a continued wet showery pattern with   
   additional moderate to locally heavy precip totals along much of   
   the California coast Ranges and into the upslope of the Sierra. A   
   broad marginal risk area was maintained from the previous outlook   
   this period with changes mostly to better fit the latest model and   
   WPC qpf. The slight risk area over Southern California in the   
   vicinity of the Transverse Range was removed given consensus of   
   additional moderate totals.   
      
   Oravec   
      
      
   Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go=   
   v/qpf/94epoints.txt__;!!DZ3fjg!5XWAwUi0fX0E08WMH2RIOHdQX8Lb6ceyz5epGnzUWH26=   
   w83e98hsTspnXECeQSomkvpdYUbkGzvjg9GKD_9T6exHWRA$=20   
   Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go=   
   v/qpf/98epoints.txt__;!!DZ3fjg!5XWAwUi0fX0E08WMH2RIOHdQX8Lb6ceyz5epGnzUWH26=   
   w83e98hsTspnXECeQSomkvpdYUbkGzvjg9GKD_9TpBJ4hNM$=20   
   Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go=   
   v/qpf/99epoints.txt__;!!DZ3fjg!5XWAwUi0fX0E08WMH2RIOHdQX8Lb6ceyz5epGnzUWH26=   
   w83e98hsTspnXECeQSomkvpdYUbkGzvjg9GKD_9TQmDnnCg$=20   
      
   =3D =3D =3D   
   To unsubscribe from WX-STORM and you already have a login, go to   
   https://lists.illinois.edu and use the "Unsubscribe" link.  Otherwise email   
   Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.   
      
   --- SBBSecho 3.28-Linux   
    * Origin: Capitol City Online (1:2320/105)   
   SEEN-BY: 1/19 100 16/0 19/10 37 104/119 105/81 106/201 114/10 120/302   
   SEEN-BY: 123/130 128/187 129/14 142/104 153/757 7715 154/10 30 50   
   SEEN-BY: 154/110 700 201/0 203/0 218/700 840 220/10 20 30 90 221/1   
   SEEN-BY: 221/6 360 226/18 30 44 50 227/114 229/110 134 206 275 300   
   SEEN-BY: 229/307 317 400 426 428 470 664 700 705 240/5832 266/512   
   SEEN-BY: 280/5003 291/111 301/1 320/119 219 319 2119 322/757 762 326/101   
   SEEN-BY: 335/364 341/66 342/200 396/45 423/81 460/58 633/280 712/848   
   SEEN-BY: 902/26 2320/0 105 304 3634/12 5020/400 5075/35   
   PATH: 2320/105 154/10 221/6 1 320/219 229/426