NAME Proposed 2004 Forecast Procedures Bob Maddox With Inputs and Help from: Erik Pytlak Art Douglas Jose Meitin Miguel Cortez And many others

TUCSON FOC Forecast operations will be located in the NWS Forecast Office Conference Room Daily weather briefings will be conducted in a classroom at the Univ of AZ Atmospheric Science Department LOGISTICS/SUPPORT JOSS and NWS TUS will: Provide forecasting and communication capabilities required for daily operations, and interactions with SMN FOC and with JOSS Operations Director and personnel on site with the aircraft Atmospheric Science will: Provide building access, office/work space and internet connectivity for scientists and students working on site in Tucson, as well as making the briefing room available for entire NAME EOP period

Proposed Daily Procedures Four FOC-produced Daily Forecast Products Analysis –Previous day summary of key features and pcpn Current –Day 1 update Forecast guidance –MOST IMPORTANT –24-48hr forecast (12 UTC Day 2 – 12UTC Day 3 Outlook –Day 3-5 –Day 6-10 Forecast Briefing - Uploaded to Field Data Catalog - Briefed to decision makers on site at Tucson

Analysis Significant “features” from previous day –MCS tracks –Large-scale features (valid 00 UTC previous day) Precip amounts, including localized maxima –Preliminary Tier-I zone verification (average for each zone) –Could also use combination of SMN, CBRFC and/or CPC grid verification? Any other images of note Completed by Assistant Forecaster

NAME Monsoon Previous-Day Analysis Date(UTC): 2004/07/30 19:28 Forecaster: Holle Submitted at(UTC): 2004/07/30 19:28 Review Previous Day Discussion: Review from July 29 12Z-July 30 12Z (see image 1 for feature map, and image 2 for areal precipitation estimate): The primary action was over Arizona (southern zone 2, western zone 4 and eastern zone 1), while large portions of the eastern and southern Tier 1 were totally suppressed. A broad area of convection west of Cabo Correntes intensified during the night and spread northeastward toward the lower end of the Gulf of California. This disturbed region may help to push additional low-level moisture up the Gulf. Discontinuous MCSs developed along the Mogollon Rim and southeast Arizona, which then move almost due west into the lower Arizona deserts. Image 3 shows yesterday's cloud-to-ground lightning strikes (CGs) over Arizona and northern Sonora - note that there were more than 17,000 CGs detected! Reports from NWS Tucson and Flagstaff indicated multiple flash flood events, especially over western Pima County (zone 1) where Doppler radar estimated localized totals up to 100mm. Significant rain amounts yesterday, all in Arizona: Ajo (central Zone 1) 45 mm; Sells (eastern edge of Zone 1) 23 mm; and Tucson (western Zone 4) 33 mm. There were no significant rains reported from SMN for the NAME Tier 1 region. The SMN precipitation map for yesterday is shown in image 4. There were no reports of measurable rain in the New Mexico portion of the Tier 1 region yesterday. Significant features of note: MCS developed seemed to be tied to an upper level divergence axis associated with IV#8 just south of Tijuana. 500mb temperatures in this area were also rather cool (<-7C), and low level moisture remains plentiful WT #26, which has generated considerable convection since Tuesday, has shown signs of additional development. SMN noted satellite imagery which indicates a low level circulation developing near 19.5N/110.0W. See SMN and NHC bulletins. IV#8 may be starting to tap into either some of this tropical moisture, or moisture from WT#27according to this morning’s satellite imagery.

Current Update Significant features (valid 00 UTC “this afternoon”) –Position and tracks of large-scale features –Updated status on tropical waves and cyclones –Expected MCSs –Expected heavy rain areas –Any moisture surges/drying trends Evaluate QPF forecast 18Z today-12Z next morning (how is yesterday’s forecast looking?) Any other images of note Completed by forecaster #2

NAME Monsoon Discussion Summary Date(UTC): 2004/07/30 19:35 Forecaster: Pytlak Submitted at(UTC): 2004/07/30 19:35 Current: Update to forecast for 30 Jul 04 12Z - 31 July 12Z (see image 1 for feature map, and image 2 for updated QPF): Significant upswing is still expected over southern Tier I as moisture from WT#21 begins to interact with IV#9 (image 3). After coordination with NHC and SMN, WT#26 may briefly form into a tropical depression, but it will quickly encounter <28C water once it reaches 20N. If anything, the lack of a strong circulation center may allow additional moisture to be shed from the tropical wave instead of concentrating around a circulation center. Farther north, expect precipitation to be lighter and concentrated over far western zone 2 (NW Arizona), while the rest of Arizona is suppressed by a cool boundary layer left over from yesterday’s activity. The QPF forecast has been adjust to increase expected precipitation over zones 7 and 8 where multiple MCSs are likely this afternoon which will then track west into the Gulf of California south of Guymas/Empalme. Significant features of note: IV#8 will remain nearly stationary near or just west of Baja Norte. Upper high center over Utah will shift east and expand into the southern U.S. Plains Two new inverted troughs may be forming, one over Texas, the other over the western Gulf of Mexico. The Texas trough should have more room to develop into a large circulation, while the western Gulf feature could become absorbed into the Texas IV which it continue to develop. WT #26, will remain strong, with some potential for tropical depression formation between now and Saturday morning. See SMN and NHC bulletins. WT#27 and 28 will remain south of Tier-I. However moisture from WT#27 may be entrained into southern Tier-I. An unnumbered cold front extending from central Texas into the lower Mississippi Valley appears too far east and too weak to affect eastern Tier-I. Expect continued suppression over zones 3 and 5.

Forecast Guidance Most important component Discussions and related “feature” graphic (valid 00 UTC “following afternoon”) will include: –Position and expected tracks of large-scale features –Expected status of tropical waves and cyclones –Expected MCSs –Expected severe thunderstorm/heavy rain areas –Any moisture surges/drying trends QPF forecast 12Z Day 2-12Z Day 3 –Areal average –Generally using the top 3 “categories” used in 2003 Outlined = Category 2 Hatched = Category 3 Solid green = Category 4 –Could include damaging wind and hail threats, too Any other images of note Completed by Briefing Forecaster

NAME Monsoon Forecast Guidance Date(UTC): 2004/07/30 19:45 Forecaster: Racy Submitted at(UTC): 2004/07/30 19:45 Forecast guidance: Valid 31 Jul 04 12Z – 01 Aug 12Z (see image 1 for feature map, and image 2 for QPF): SMN, HPC and FOC all agree on potential for widespread MCS activity, and perhaps a full MCC, affecting much of central and southern Tier I. If MCSs develop and propagate across the southern end of the Gulf of California, another moisture surge is likely which will spread into zones 1, 2 and 6. It is important to note that areas farther north are already quite moist, so Gulf Surge criteria will not be met. Development is more likely over southern Tier-I, depending on how widespread the convection is today. It is still unclear which developing IV to the east of Tier I will have the greatest impact. However with the northern IV being the larger of the two, and with increasing 200mg winds on it’s north side, the northern IV looks more promising. Models are in some disagreement, with the GFS and NGM emphasizing the northern IV, while Eta and SMN MM-5 emphasizing the southern one. Either way, southern and central Tier I will be in strong upper level divergence and/or deformation as the IVs move west, while the persistent IV just west of the Baja Peninsula remains nearly stationary. Best juxtaposition of dry subcloud layers, hottest surface temperatures, and broad upper divergence indicate the greatest threat of high winds, in addition to the heavy rain, will be between the Sierra Madres and the Sonoran coast. WT#26, which may briefly form into a TC (it would be TC#5E), may have already served its purpose in feeding considerable moisture into Tier- I. WT #27 and 28 will pass well to the south, but the persistent IV off the Baja coast may tap more moisture from oe nor both of these waves. Significant features of note: IV#8 will remain nearly stationary near or just west of Baja Norte. A new IV (IV#9) over Texas will drift into the Big Bend area, inducing increasing upper divergence and weakening upper static stability over a broad area of the Sierra Madres. A new IV (IV#10) may form along the Mexican Gulf Coast, but may eventually be absorbed into IV#10. Upper high center over Colorado will continue to expand into the southern U.S. Plains Although Gulf Surge criteria will be met, outflows and pressure differentials will support significant moisture transport into the northern Gulf and eventually the lower deserts of Arizona and SE California.

Outlook Days 3-5 –Brief discussion of expected trends –Focus on only persistent features Upper anticyclones Tropical cyclones Large pattern changes –Additional images optional –Completed by HPC or FOC Days 6-10 –Brief discussion if a large-scale change is possible –Focus on climatological features Large/persistent pattern changes MJO evolution –Completed by CPC or FOC

NAME Monsoon Extended Outlook Date(UTC): 2004/07/30 19:45 Forecasters: Pytlak (FOC)/Handel (CPC) Submitted at(UTC): 2004/07/30 19:45 Day 3-5 and Day 6-10 Outlook: Valid 01 Aug 12Z – 07 Aug 12Z: Day 3-5: No real long-term changes are expected. Upper subtropical high over the U.S. southern Plains will continue to feed a series of IVs across central Tier I, with WTs clipping southern Tier I. SMN analyses this morning show at least 6 WTs lined up from the Gulf of Tehuantepec into the central Atlantic. Any of these WTs could develop into tropical cyclones with mb shear over the eastern Pacific expected to remain low. The northwest quarter of Tier I (Zones 3 and 5) are the least likely areas to receive significant thunderstorm activity due to their close proximity to the upper high center. Off the Baja coast, the persistent inverted trough (IV#8), which is more of an extension of the large-scale and seasonal subtropical trough, shows no signs of weakening or being lifted north. Day 6-10: There is some indication that a weak phase of the MJO will propagate out of the central Pacific and into the NAM region. GFS ensembles at 168 hrs indicate a slight breakdown in the upper ridge over the central U.S. image 1, which would suggest the possibility of westerly flow impingement over northern Tier-I. See image 2 for a the 5- and 30-day moving MJO indices.