WEEKLY WEATHER OUTLOOK BELIZE, CENTRAL AMERICA PERIOD: Sunday, July 1 until Monday, July 9, 2012 DATE ISSUED: Sunday, July 1, 2012 3:00 pm RFrutos EcoSolutions & Services SYNOPSIS: The features of interest this coming week will be the approach and passage of two tropical waves. The first will reach Belize later Tuesday and early Wednesday. The second and much more active tropical wave will show its presence late Saturday through Sunday. The approach and passage of this system will force a northward shift in the Inter tropical convergence zone (ITCZ) over northern Central America and an influx of moisture from the Pacific. Also, the TW wave will traverse northern Central America ahead of a surge in the low level easterlies, which will also favor intense thunderstorm outbreaks (Figure 5 below). Figure 1 GOES IR Satellite picture for 3:00 pm, Sunday July 1, 2012, showing only weak convective cells in the NW Caribbean, with heavier convection over southern and central Guatemala. The mainland of Belize and coastal waters is almost free of convection around at this time. 1
Conditions will become favorable for outbreaks of showers and on Monday and Tuesday as a weak tropical wave traverses the NW Caribbean and cross Belize Tuesday night or early Wednesday. Moisture and instability will be on the increase as we move into the weekend with the approach and passage of another more active tropical wave later on Saturday and Sunday morning. Coupled with this second tropical wave will be an influx on moisture from the Pacific, as the ITCZ shifts northwards over Central America and the leading edge of a surge in the easterlies over the Caribbean reach the extreme NW Caribbean region. Daytime heating and the passage of the tropical waves will induce outbreaks of showers and over Belize and coastal waters during most of this working, and will increase over the weekend. Model projections suggest that the bulk of the rainfall will be concentrated over the central and northern coastal regions at first, but will become more widespread later on Friday through Sunday. Daily rainfall accumulations will range from 0.25-1.00 on Sunday through Wednesday, especially over the coast and northern areas. Expect higher rainfall amounts in the hilly terrain of the Stann Creek and Toledo Districts, and NE Cayo District. Daily rainfall totals on Thursday through Monday of next week will be ranging from 0.75-2.00 es, especially along the coast and in the Hills. Folks in low lying areas should remain vigilant this week and be prepared to move to higher grounds if necessary particularly on Sunday and Monday of next week! Belize Seven-day Outlook for Agriculture and Industry Sun Mon Tue Wed Thu Fri Sat July 1, 2012 July 2, 2012 July 3, 2012 July 4, 2012 July 5, 2012 July 6, 2012 July 7, 2012 2
Sunny with cloudy periods; few showers mostly inland 0.25-0.50 of-an Sunny with cloudy periods; few mostly inland 0.50-1.00 Cloudy with scattered mostly coast & north 0.50 1.50 Cloudy with scattered mostly coast & north 0.50 1.00 Cloudy with a few mostly central coast 0.50 1.00 Cloudy with a few mostly along the coast Hills 0.75-1.50 Cloudy with more outbreaks of increasing 1.00-1.75 Figure 2 Surface map valid for 3:00 am Monday, June 25, 2012, showing TS Debby in the NE Gulf of Mexico almost stationary, with 50 mph maximum sustained one- minute winds. Weak pressure gradient over the NW Caribbean and Belize. Figure 3 NHC 72- hr forecast surface map valid for 6:00 am Wednesday, July 4, 2012, showing TW near the coast of Yucatan and Belize. A second TW is evident over the eastern Caribbean, heading westward at 15 mph. 3
This second TW will reach Belize late Saturday and Sunday. Figure 4 GFS model daily rainfall projection at 168 hours, valid 12:00 pm, Sunday July 8, 2012, showing ITCZ lifting north over Central America and TW over Belize, generating rainfall of 1.50-2.00 es from Saturday afternoon until noon on Sunday. Rainfall concentrated mostly over central and northern coast. Fig. 5 GFS Model vorticity projection at 5,000 ft level or 850 mb, valid for 12:00 pm Sunday, July 8, 2012, showing vorticity maximum (or low pressure center) moving into the Gulf of Honduras, and generating more outbreaks of showers and across Belize, some intense at times. Voticity max 4
depicted in yellow with center marked with an x OUTLOOK FOR THE MAIN DEVELOPMENT REGION (MDR) OF THE TROPICAL ATLANTIC BASIN ABNT20 KNHC 251117 TWOAT TROPICAL WEATHER OUTLOOK NWS NATIONAL HURRICANE CENTER MIAMI FL 500 AM EDT SUN JULY 1 2012; 3:00 pm LOCAL TIME BELIZE FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO... TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE NEXT 48 HOURS. FORECASTER PASCH Summary of Atlantic Basin 2012 Hurricane Season Forecast: Tropical Cyclones NHC 1981-2010 Seasonal Average CSU (Klotzbach & Gray) NOAA INSMET (Cuba) Named Storms (NS) 12 10 9-15 10 Hurricanes (H) 6 4 4-8 5 Major Hurricanes 3 2 1-3 -- Atlantic NS 7.1 (INSMET) 8 Caribbean NS 1.5 (INSMET) 1 Gulf of Mexico NS 2.0 (INSMET) 1 Probability of at least one moving through the Caribbean Sea from Atlantic 50% (INSMET) 55% Probability of at least one forming and reaching hurricane intensity within the Caribbean Sea 43% (INSMET) 15% 5
Expected 2012 activity in the Atlantic Basin Climate signals and evolving oceanic and atmospheric conditions, combined with dynamical model forecasts, indicate that a near-normal 2012 Atlantic hurricane season is most likely. This outlook calls for a 50% chance of a near-normal season, a 25% chance of an above-normal season, and a 25% chance of a below normal season. An important measure of the total overall seasonal activity is NOAA s Accumulated Cyclone Energy (ACE) index, which accounts for the intensity and duration of named storms and hurricanes during the season. This outlook indicates a 70% chance that the 2012 seasonal ACE range will be 65%-140% of the median. According to NOAA s hurricane season classifications, an ACE value above 111% of the 1981-2010 median reflects an above-normal season. An ACE value below 71.4% of the median reflects a below-normal season. Consistent with the expected ACE range, the 2012 Atlantic hurricane season is predicted to produce (with 70% probability for each range) 9-15 named storms, of which 4-8 are expected to become hurricanes, and 1-3 are expected to become major hurricanes. These ranges are centered near the 1981-2010 period averages of 12 named storms, 6 hurricanes and 3 major hurricanes. (Source: NOAA, June 2012) 6